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León Félix L, Sanz B, Sebastián V, Torres TE, Sousa MH, Coaquira JAH, Ibarra MR, Goya GF. Gold-decorated magnetic nanoparticles design for hyperthermia applications and as a potential platform for their surface-functionalization. Sci Rep 2019; 9:4185. [PMID: 30862882 PMCID: PMC6414712 DOI: 10.1038/s41598-019-40769-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 02/11/2019] [Indexed: 11/09/2022] Open
Abstract
The integration of noble metal and magnetic nanoparticles with controlled structures that can couple various specific effects to the different nanocomposite in multifunctional nanosystems have been found interesting in the field of medicine. In this work, we show synthesis route to prepare small Au nanoparticles of sizes = 3.9 ± 0.2 nm attached to Fe3O4 nanoparticle cores ( = 49.2 ± 3.5 nm) in aqueous medium for potential application as a nano-heater. Remarkably, the resulted Au decorated PEI-Fe3O4 (Au@PEI-Fe3O4) nanoparticles are able to retain bulk magnetic moment MS = 82-84 Am2/kgFe3O4, with the Verwey transition observed at TV = 98 K. In addition, the in vitro cytotoxicity analysis of the nanosystem microglial BV2 cells showed high viability (>97.5%) to concentrate up to 100 µg/mL in comparison to the control samples. In vitro heating experiments on microglial BV2 cells under an ac magnetic field (H0 = 23.87 kA/m; f = 571 kHz) yielded specific power absorption (SPA) values of SPA = 43 ± 3 and 49 ± 1 μW/cell for PEI-Fe3O4 and Au@PEI-Fe3O4 NPs, respectively. These similar intracellular SPA values imply that functionalization of the magnetic particles with Au did not change the heating efficiency, providing at the same time a more flexible platform for multifunctional functionalization.
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Affiliation(s)
- L León Félix
- Laboratory of Magnetic Characterization, Instituto de Física, Universidade de Brasília, Brasília, DF, 70910-900, Brazil.
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, 50018, Spain.
| | - B Sanz
- nB nanoScale Biomagnetics S.L., Zaragoza, Spain
| | - V Sebastián
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Networking Research Centre on Bioengineering, Biomaterials and Nanomedicine, CIBER-BBN, 28029, Madrid, Spain
| | - T E Torres
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Laboratorio de Microscopias Avanzadas (LMA), Universidad de Zaragoza, Zaragoza, 50018, Spain
| | - M H Sousa
- Green Nanotechnology Group, University of Brasília, Brasília, DF, 72220-900, Brazil
| | - J A H Coaquira
- Laboratory of Magnetic Characterization, Instituto de Física, Universidade de Brasília, Brasília, DF, 70910-900, Brazil
| | - M R Ibarra
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, 50018, Spain
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, 50009, Spain
| | - G F Goya
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, 50018, Spain.
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, 50009, Spain.
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Michalik JM, Rybicki D, Tarnawski Z, Sikora M, De Teresa JM, Ibarra MR, Kapusta C. 55Mn NMR observation of colossal magnetoresistance effect in Sm 0.55Sr 0.45MnO 3. J Phys Condens Matter 2017; 29:265802. [PMID: 28498111 DOI: 10.1088/1361-648x/aa72c5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Temperature dependent 55Mn NMR study of Sm0.55Sr0.45MnO3 is reported. Previous bulk magnetization measurements have shown that below T C ~ 125 K the sample is ferromagnetic metallic (FMM) and above TC it is charge ordered and insulating. In present report, we show that from zero-field NMR a single line double-exchange (DE) signal is observed at temperatures up to 139 K, which is due to a presence of FMM clusters also above T C. The intensity of the DE line follows the temperature dependence of the magnetization measured at 0.01 T. When a magnetic field up to 2 T is applied at 139 K (i.e. 14 K above T C), a strong increase in NMR intensity of the DE line is observed indicating that content of FMM regions increases. This reveals that metallicity is induced in the material by the applied magnetic field and explains the observed colossal magnetoresistance (CMR) effect at the microscopic level. The observation agrees with previous results, which confirm that the percolation of the FMM clusters is responsible for the CMR effect. The shift of the resonant frequency in the applied field is three times smaller compared to decrease expected from gyromagnetic ratio, which indicates an antiferromagnetic coupling between the FMM clusters.
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Affiliation(s)
- J M Michalik
- Faculty of Physics and Applied Computer Science, Department of Solid State Physics, AGH University of Science and Technology, Al. Mickiewicza, 30-059 Krakow, Poland
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Rodríguez LA, Magén C, Snoeck E, Gatel C, Castán-Guerrero C, Sesé J, García LM, Herrero-Albillos J, Bartolomé J, Bartolomé F, Ibarra MR. High-resolution imaging of remanent state and magnetization reversal of superdomain structures in high-density cobalt antidot arrays. Nanotechnology 2014; 25:385703. [PMID: 25181396 DOI: 10.1088/0957-4484/25/38/385703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Remanent state and magnetization reversal processes of a series of cobalt antidot arrays with a fixed hole diameter (d ≈ 55 nm) and an array periodicity (p) ranging between 95 and 524 nm were studied by in situ Lorentz microscopy (LM) as a function of the magnetic field. At remanence, defocused LM images showed the periodicity dependence of the magnetic states inside the lattice. A remarkable transition was observed in the type of domain structures as a function of p: for the large periodicities (p > 300 nm), conventional 90° and 180° domain walls were formed, whereas in small-period antidot arrays (p ≦ 160 nm) magnetic superdomain walls (SDWs) were nucleated to separate regions with different average magnetization direction, the so-called magnetic superdomains. In the SDW regime, a low-frequency Fourier filtering method was implemented to allow a quantitative analysis of the LM images by the transport of intensity equation method. In situ LM experiments under applied magnetic fields were performed to study the reversal magnetization process in a particular array (p = 160 nm), and clear differences were observed as a function of the magnetic field orientation. The switching process under magnetic fields parallel to the horizontal antidot rows occurs in two stages: the system first nucleates and propagates horizontal SDWs, parallel to the field. Then, at higher magnetic fields, vertical SDWs, perpendicular to the field, appear before saturation. When the magnetic field is applied at 45° with respect to the antidot rows, both horizontal and vertical SDWs are nucleated and propagated simultaneously. All the experiments were successfully correlated with micromagnetic simulations. The current study sheds new light on the magnetization reversal processes of antidot arrays and opens new possibilities of exploiting the potential of high-resolution in situ LM and new data analysis procedures to probe magnetization processes in nanomagnetism, particularly in periodic arrays of nanomagnets.
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Affiliation(s)
- L A Rodríguez
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain. Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain. Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse, France. CEMES-CNRS 29, rue Jeanne Marvig, B.P. 94347 F-31055, Toulouse Cedex, France
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Serrano-Ramón L, Fernández-Pacheco A, Córdoba R, Magén C, Rodríguez LA, Petit D, Cowburn RP, Ibarra MR, De Teresa JM. Improvement of domain wall conduit properties in cobalt nanowires by global gallium irradiation. Nanotechnology 2013; 24:345703. [PMID: 23899474 DOI: 10.1088/0957-4484/24/34/345703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Applications based on the movement of domain walls (DWs) in magnetic nanowires (NWs) require a good DW conduit behavior, i.e. a significant difference between DW nucleation and propagation fields. In this work, we have systematically studied how this property evolves in cobalt NWs grown by focused electron beam induced deposition (FEBID) as a function of global gallium irradiation, for irradiation doses up to 1.24 × 10(17) ions cm(-2). Whereas for high doses the DW conduit is lost, below 6.42 × 10(15) ions cm(-2) the difference between the two fields increases with irradiation, becoming up to ∼9 times larger than for non-irradiated wires, due to a strong increase in the nucleation field, while the propagation field remains approximately constant. This behavior stems from two effects. The first effect is a decrease in the magnetic volume of the parasitic halo around the NW, typically present in FEBID nanostructures, leading to the disappearance of weak nucleation centers. The second effect is the formation of a 20 nm outer shell with Co crystals about twice the size of those forming the NW core, causing a net increase of the local magnetocrystalline anisotropy. The results presented here are important for the potential use of magnetic NWs grown by FEBID in DW-based devices, and might also be of interest for magnetic NWs fabricated by other techniques.
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Affiliation(s)
- L Serrano-Ramón
- Instituto de Ciencia de Materiales de Aragón, Facultad de Ciencias, Universidad de Zaragoza-CSIC, E-50009, Zaragoza, Spain
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Rodríguez LA, Magén C, Snoeck E, Gatel C, Marín L, Serrano-Ramón L, Prieto JL, Muñoz M, Algarabel PA, Morellon L, De Teresa JM, Ibarra MR. Quantitative in situ magnetization reversal studies in Lorentz microscopy and electron holography. Ultramicroscopy 2013; 134:144-54. [PMID: 23831132 DOI: 10.1016/j.ultramic.2013.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Revised: 06/05/2013] [Accepted: 06/07/2013] [Indexed: 10/26/2022]
Abstract
A generalized procedure for the in situ application of magnetic fields by means of the excitation of the objective lens for magnetic imaging experiments in Lorentz microscopy and electron holography is quantitatively described. A protocol for applying magnetic fields with arbitrary in-plane magnitude and orientation is presented, and a freeware script for Digital Micrograph(™) is provided to assist the operation of the microscope. Moreover, a method to accurately reconstruct hysteresis loops is detailed. We show that the out-of-plane component of the magnetic field cannot be always neglected when performing quantitative measurements of the local magnetization. Several examples are shown to demonstrate the accuracy and functionality of the methods.
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Affiliation(s)
- L A Rodríguez
- Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Zaragoza, Spain; Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain; Transpyrenean Associated Laboratory for Electron Microscopy (TALEM), CEMES-INA, CNRS-Universidad de Zaragoza, Toulouse, France; CEMES-CNRS 29, rue Jeanne Marvig, B.P. 94347, F-31055 Toulouse Cedex, France
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Grazú V, Silber AM, Moros M, Asín L, Torres TE, Marquina C, Ibarra MR, Goya GF. Application of magnetically induced hyperthermia in the model protozoan Crithidia fasciculata as a potential therapy against parasitic infections. Int J Nanomedicine 2012; 7:5351-60. [PMID: 23071396 PMCID: PMC3469100 DOI: 10.2147/ijn.s35510] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Magnetic hyperthermia is currently a clinical therapy approved in the European Union for treatment of tumor cells, and uses magnetic nanoparticles (MNPs) under time-varying magnetic fields (TVMFs). The same basic principle seems promising against trypanosomatids causing Chagas disease and sleeping sickness, given that the therapeutic drugs available have severe side effects and that there are drug-resistant strains. However, no applications of this strategy against protozoan-induced diseases have been reported so far. In the present study, Crithidia fasciculata, a widely used model for therapeutic strategies against pathogenic trypanosomatids, was targeted with Fe3O4 MNPs in order to provoke cell death remotely using TVMFs. Methods Iron oxide MNPs with average diameters of approximately 30 nm were synthesized by precipitation of FeSO4 in basic medium. The MNPs were added to C. fasciculata choanomastigotes in the exponential phase and incubated overnight, removing excess MNPs using a DEAE-cellulose resin column. The amount of MNPs uploaded per cell was determined by magnetic measurement. The cells bearing MNPs were submitted to TVMFs using a homemade AC field applicator (f = 249 kHz, H = 13 kA/m), and the temperature variation during the experiments was measured. Scanning electron microscopy was used to assess morphological changes after the TVMF experiments. Cell viability was analyzed using an MTT colorimetric assay and flow cytometry. Results MNPs were incorporated into the cells, with no noticeable cytotoxicity. When a TVMF was applied to cells bearing MNPs, massive cell death was induced via a nonapoptotic mechanism. No effects were observed by applying TVMF to control cells not loaded with MNPs. No macroscopic rise in temperature was observed in the extracellular medium during the experiments. Conclusion As a proof of principle, these data indicate that intracellular hyperthermia is a suitable technology to induce death of protozoan parasites bearing MNPs. These findings expand the possibilities for new therapeutic strategies combating parasitic infection.
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Affiliation(s)
- V Grazú
- Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, Spain
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García-García A, Pardo JA, Strichovanec P, Magén C, Vovk A, De Teresa JM, Kakazei GN, Pogorelov YG, Golub V, Salyuk O, Morellón L, Algarabel PA, Ibarra MR. Magnetic properties of epitaxial discontinuous Fe/MgO multilayers. J Nanosci Nanotechnol 2012; 12:7505-7509. [PMID: 23035505 DOI: 10.1166/jnn.2012.6548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report magnetic, dynamic and transport properties of discontinuous metal-insulator multilayers Fe/MgO grown on amorphous Corning glass and single-crystalline MgO (001) substrates. The films of structure Substrate/MgO (3 nm)/[Fe (0.6 nm)/MgO (3.0 nm)] x 10 were prepared in ultra-high vacuum conditions using Pulsed Laser Deposition. It was shown that conditions of epitaxial growth are favorable for MgO substrates. As a result a substantial increase of tunneling magnetoresistance caused by spin-filtering effect was observed and reasonably theoretically explained. The value of TMR - 9.2% at room temperature in 18 kOe magnetic field is three times higher comparing to that for the samples grown on Corning glass substrates.
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Fernández-Pacheco A, Serrano-Ramón LE, Tyliszczak T, Chou KW, Córdoba R, Szkudlarek A, Brien LO, Kapusta C, Ibarra MR, De Teresa JM. Correlation between the magnetic imaging of cobalt nanoconstrictions and their magnetoresistance response. Nanotechnology 2012; 23:105703. [PMID: 22361492 DOI: 10.1088/0957-4484/23/10/105703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Scanning transmission x-ray microscopy (STXM) and magnetoresistance (MR) measurements are used to investigate the magnetic behavior of a nanoconstriction joining two micrometric electrodes (a pad and a wire). The reversal of the magnetization under variable external static magnetic fields is imaged. By means of a detailed analysis of the STXM images at the nanocontact area, the MR is calculated, based on diffusive anisotropic-MR. This MR agrees well with that obtained from electrical transport measurements, allowing a direct correlation between the MR signal and the magnetic reversal of the system. The magnetization behavior depends on the sample thickness and constriction dimensions. In 40 nm-thick samples, with 20 × 175 nm(2) contact areas, the magnetization at the two sides of the constriction forms a net angle of 90°, with a progressive evolution of the magnetization structure between the electrodes during switching. The MR in those cases has a more peaked shape than with 20 nm-thick electrodes and 10 × 80 nm(2) contact areas, where the magnetization forms 180° between them, with a wide domain wall pinned at the constriction. As a consequence of this configuration, a plateau in the MR is observed for about 20 Oe.
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Affiliation(s)
- A Fernández-Pacheco
- Instituto de Ciencia de Materiales de Aragón (ICMA), Departamento de Física de la Materia Condensada, Universidad de Zaragoza-CSIC, Pedro Cerbuna 12, Zaragoza, Spain.
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Asín L, Ibarra MR, Tres A, Goya GF. Controlled cell death by magnetic hyperthermia: effects of exposure time, field amplitude, and nanoparticle concentration. Pharm Res 2012; 29:1319-27. [PMID: 22362408 DOI: 10.1007/s11095-012-0710-z] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 02/15/2012] [Indexed: 01/07/2023]
Abstract
PURPOSE To investigate the effects of alternating magnetic fields (AMF) on the death rate of dendritic cells (DCs) loaded with magnetic nanoparticles (MNPs) as heating agents. AMF exposure time and amplitude as well as the MNPs concentration were screened to assess the best conditions for a controlled field-induced cell death. METHODS Human-monocyte-derived DCs were co-incubated with dextran-coated MNPs. The cells were exposed to AMF (f = 260 kHz; 0 < H(0) < 12.7 kA/m) for intervals from 5 to 15 min. Morphology changes were assessed by scanning electron microscopy. Cell viability was measured by Trypan blue and fluorescence-activated cell sorting (FACS) using Annexin-propidium iodide markers. RESULTS We were able to control the DCs viability by a proper choice AMF amplitude and exposure time, depending on the amount of MNPs uploaded. About 20% of cells showed Annexin-negative/PI-positive staining after 5-10 min of AMF exposure. CONCLUSIONS Controlled cell death of MNP-loaded DCs can be obtained by adequate tuning of the physical AMF parameters and MNPs concentration. Necrotic-like populations were observed after exposure times as short as 10 min, suggesting a fast underlying mechanism for cell death. Power absorption by the MNPs might locally disrupt endosomic membranes, thus provoking irreversible cell damage.
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Affiliation(s)
- L Asín
- Instituto de Nanociencia de Aragón, University of Zaragoza, Mariano Esquillor, 50018 Zaragoza, Spain
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Schoenaker FJ, Córdoba R, Fernández-Pacheco R, Magén C, Stéphan O, Zuriaga-Monroy C, Ibarra MR, De Teresa JM. Focused electron beam induced etching of titanium with XeF2. Nanotechnology 2011; 22:265304. [PMID: 21586811 DOI: 10.1088/0957-4484/22/26/265304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Titanium is a relevant technological material due to its extraordinary mechanical and biocompatible properties, its nanopatterning being an increasingly important requirement in many applications. We report the successful nanopatterning of titanium by means of focused electron beam induced etching using XeF(2) as a precursor gas. Etch rates up to 1.25 × 10(-3) µm(3) s(-1) and minimum pattern sizes of 80 nm were obtained. Different etching parameters such as beam current, beam energy, dwell time and pixel spacing are systematically investigated, the etching process being optimized by decreasing both the beam current and the beam energy. The etching mechanism is investigated by transmission electron microscopy. Potential applications in nanotechnology are discussed.
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Affiliation(s)
- F J Schoenaker
- Instituto de Nanociencia de Aragón, Universidad de Zaragoza, Zaragoza, Spain
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Pereira C, Alves C, Monteiro A, Magén C, Pereira AM, Ibarra A, Ibarra MR, Tavares PB, Araújo JP, Blanco G, Pintado JM, Carvalho AP, Pires J, Pereira MFR, Freire C. Designing novel hybrid materials by one-pot co-condensation: from hydrophobic mesoporous silica nanoparticles to superamphiphobic cotton textiles. ACS Appl Mater Interfaces 2011; 3:2289-99. [PMID: 21615151 DOI: 10.1021/am200220x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This work reports the synthesis and characterization of mesoporous silica nanoparticles (MSNs) functionalized with tridecafluorooctyltriethoxysilane (F13) and their in situ incorporation onto cotton textiles. The hybrid MSNs and the functional textiles were prepared by a one-pot co-condensation methodology between tetraethylorthosilicate (TEOS) and F13, with hexadecyltrimethylammonium chloride (CTAC) as the template and triethanolamine as the base. The influence of the F13 to TEOS molar ratio (1:10, 1:5 and 1:3) on the nanoparticle morphology, porosity, degree of functionalization, and hydro/oleophobic properties is discussed. The hybrid nanosilicas presented high colloidal stability and were spherical and monodispersed with average particle size of ∼45 nm. They also showed high surface areas, large pore volumes, and a wormhole-type mesoporous structure. The increase in the organosilane proportion during the co-condensation process led to a more radially branched wormhole-like mesoporosity, a decrease in the surface area, pore volume, and amount of surface silanol groups, and an enrichment of the surface with fluorocarbon moieties. These changes imparted hydrophobic and oleophobic properties to the materials, especially to that containing the highest F13 loading. Cotton textiles were coated with the F13-MSNs through an efficient and less time-consuming route. The combination between surface roughness and mesoporosity imparted by the MSNs, and the low surface energy provided by the organosilane resulted in superhydrophobic functional textiles. Moreover, the textile with the highest loading of fluorocarbon groups was superamphiphobic.
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Affiliation(s)
- C Pereira
- REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, 4169-007 Porto, Portugal
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Marcos-Campos I, Asín L, Torres TE, Marquina C, Tres A, Ibarra MR, Goya GF. Cell death induced by the application of alternating magnetic fields to nanoparticle-loaded dendritic cells. Nanotechnology 2011; 22:205101. [PMID: 21444956 DOI: 10.1088/0957-4484/22/20/205101] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In this work, the capability of primary, monocyte-derived dendritic cells (DCs) to uptake iron oxide magnetic nanoparticles (MNPs) is assessed and a strategy to induce selective cell death in these MNP-loaded DCs using external alternating magnetic fields (AMFs) is reported. No significant decrease in the cell viability of MNP-loaded DCs, compared to the control samples, was observed after five days of culture. The number of MNPs incorporated into the cytoplasm was measured by magnetometry, which confirmed that 1-5 pg of the particles were uploaded per cell. The intracellular distribution of these MNPs, assessed by transmission electron microscopy, was found to be primarily inside the endosomic structures. These cells were then subjected to an AMF for 30 min and the viability of the blank DCs (i.e. without MNPs), which were used as control samples, remained essentially unaffected. However, a remarkable decrease of viability from approximately 90% to 2-5% of DCs previously loaded with MNPs was observed after the same 30 min exposure to an AMF. The same results were obtained using MNPs having either positive (NH(2)(+)) or negative (COOH(-)) surface functional groups. In spite of the massive cell death induced by application of AMF to MNP-loaded DCs, the number of incorporated magnetic particles did not raise the temperature of the cell culture. Clear morphological changes at the cell structure after magnetic field application were observed using scanning electron microscopy. Therefore, local damage produced by the MNPs could be the main mechanism for the selective cell death of MNP-loaded DCs under an AMF. Based on the ability of these cells to evade the reticuloendothelial system, these complexes combined with an AMF should be considered as a potentially powerful tool for tumour therapy.
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Guillamón I, Suderow H, Vieira S, Sesé J, Córdoba R, De Teresa JM, Ibarra MR. Direct observation of stress accumulation and relaxation in small bundles of superconducting vortices in tungsten thin films. Phys Rev Lett 2011; 106:077001. [PMID: 21405532 DOI: 10.1103/physrevlett.106.077001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Revised: 11/24/2010] [Indexed: 05/30/2023]
Abstract
We study the behavior of bundles of superconducting vortices when increasing the magnetic field using scanning tunneling microscopy and spectroscopy at 100 mK. Pinning centers are given by features on the surface corrugation. We find strong net vortex motion in a bundle towards a well-defined direction. We observe continuous changes of the vortex arrangements, and identify small displacements, which stress and deform the vortex bundle, separated by larger rearrangements or avalanches, which release accumulated stress.
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Affiliation(s)
- I Guillamón
- Laboratorio de Bajas Temperaturas, Departamento de Física de la Materia Condensada, Instituto de Ciencia de Materiales Nicolás Cabrera, Facultad de Ciencias, Universidad Autónoma de Madrid, Spain
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Lavrijsen R, Córdoba R, Schoenaker FJ, Ellis TH, Barcones B, Kohlhepp JT, Swagten HJM, Koopmans B, De Teresa JM, Magén C, Ibarra MR, Trompenaars P, Mulders JJL. Fe:O:C grown by focused-electron-beam-induced deposition: magnetic and electric properties. Nanotechnology 2011; 22:025302. [PMID: 21135470 DOI: 10.1088/0957-4484/22/2/025302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We systematically study the effect of oxygen content on the magneto-transport and microstructure of Fe:O:C nanowires deposited by focused-electron-beam-induced (FEBID) deposition. The Fe/O ratio can be varied with an Fe content varying between ∼ 50 and 80 at.% with overall low C content (≈16 ± 3 at.%) by adding H(2)O during the deposition while keeping the beam parameters constant as measured by energy dispersive x-ray (EDX) spectroscopy. The room-temperature magnetic properties for deposits with an Fe content of 66-71 at.% are investigated using the magneto-optical Kerr effect (MOKE) and electric magneto-transport measurements. The nanostructure of the deposits is investigated through cross-sectional high-resolution transmission electron microscopy (HRTEM) imaging, allowing us to link the observed magneto-resistance and resistivity to the transport mechanism in the deposits. These results demonstrate that functional magnetic nanostructures can be created, paving the way for new magnetic or even spintronics devices.
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Affiliation(s)
- R Lavrijsen
- Department of Applied Physics, Eindhoven University of Technology, Eindhoven, The Netherlands.
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Hernández R, Sacristán J, Asín L, Torres TE, Ibarra MR, Goya GF, Mijangos C. Magnetic Hydrogels Derived from Polysaccharides with Improved Specific Power Absorption: Potential Devices for Remotely Triggered Drug Delivery. J Phys Chem B 2010; 114:12002-7. [DOI: 10.1021/jp105556e] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Hernández
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - J. Sacristán
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - L. Asín
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - T. E. Torres
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - M. R. Ibarra
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - G. F. Goya
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - C. Mijangos
- Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid, Spain, Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, 50018 Spain, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
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Torres TE, Roca AG, Morales MP, Ibarra A, Marquina C, Ibarra MR, Goya GF. Magnetic properties and energy absorption of CoFe2O4nanoparticles for magnetic hyperthermia. ACTA ACUST UNITED AC 2010. [DOI: 10.1088/1742-6596/200/7/072101] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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17
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García-García A, Vovk A, Strichovanec P, Pardo JA, Magén C, Algarabel PA, De Teresa JM, Morellón L, Ibarra MR. Determination of the percolation threshold in Fe/MgO magnetic granular multilayers. J Phys Condens Matter 2010; 22:056003. [PMID: 21386355 DOI: 10.1088/0953-8984/22/5/056003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The evolution of the morphology, magnetic and transport properties of Fe(t nm)/MgO(3.0 nm) multilayers with respect to the nominal metallic layer thickness was investigated. A comparison with existing experimental data on discontinuous metal-insulator multilayers, ultrathin epitaxial Fe films on MgO substrates and granular cermet films is made. It is confirmed that the deposition conditions and the material composition play a crucial role in the percolation process. Nominal thicknesses of Fe layers at which an infinite metallic cluster is formed and the conditions for continuous Fe coverage were determined. Different methods of percolation threshold detection were analysed. We show that investigation of the temperature dependence of resistance in nanostructures could lead to an overestimation of the percolation threshold value, while magnetic measurements alone could lead to its underestimation.
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Affiliation(s)
- A García-García
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, 50009-Zaragoza, Spain. Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009-Zaragoza, Spain
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Fernández-Pacheco A, De Teresa JM, Szkudlarek A, Córdoba R, Ibarra MR, Petit D, O'Brien L, Zeng HT, Lewis ER, Read DE, Cowburn RP. Magnetization reversal in individual cobalt micro- and nanowires grown by focused-electron-beam-induced-deposition. Nanotechnology 2009; 20:475704. [PMID: 19858555 DOI: 10.1088/0957-4484/20/47/475704] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We systematically study individual micro- and nanometric polycrystalline cobalt wires grown by focused-electron-beam-induced-deposition. The deposits were grown in a range of aspect ratios varying from 1 up to 26. The minimum lateral dimension of the nanowires was 150 nm, for a thickness of 40 nm. Atomic force microscopy images show beam-current-dependent profiles, associated with different regimes of deposition. The magnetization reversal of individual nanowires is studied by means of the spatially resolved magneto-optical Kerr effect. Abrupt switching is observed, with a systematic dependence on the wire's dimensions. This dependence of the coercive field is understood in magnetostatic terms, and agrees well with previous results on cobalt wires grown with different techniques. The influence of compositional gradients along the structural profile on the magnetic reversal is studied by using micromagnetic simulations. This work demonstrates the feasibility of using this technique to fabricate highly pure magnetic nanostructures, and highlights the advantages and disadvantages of the technique with respect to more conventional ones.
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Affiliation(s)
- A Fernández-Pacheco
- Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50009 Zaragoza, Spain
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Fernández-Pacheco A, De Teresa JM, Córdoba R, Ibarra MR. Exploring the conduction in atomic-sized metallic constrictions created by controlled ion etching. Nanotechnology 2008; 19:415302. [PMID: 21832642 DOI: 10.1088/0957-4484/19/41/415302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel technique to establish atomic-sized contacts in metallic materials is shown. It is based on etching a (sub)micrometric electrode via a low-energy focused ion beam. The in situ measurements of the nanoconstriction resistance during the etching process permit control of the formation of atomic-sized constrictions with milling time, observing steps in the conductance in the range of the conductance quantum (G(0) = 2e(2)/h), just before entering the tunnelling regime. These constrictions are highly stable with time due to the adherence to a substrate, which allows further studies such as the detailed current-voltage transport investigation reported here. Scanning electron microscopy images are used to correlate the etching process and the constriction microstructure. The high control achieved in the process makes us suggest this technique as a promising route to study physical phenomena in the verge of the metal-tunnel conduction crossover.
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Affiliation(s)
- A Fernández-Pacheco
- Instituto de Nanociencia de Aragón, Universidad de Zaragoza, Zaragoza, 50009, Spain. Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Facultad de Ciencias, Zaragoza, 50009, Spain
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Goya GF, Marcos-Campos I, Fernández-Pacheco R, Sáez B, Godino J, Asín L, Lambea J, Tabuenca P, Mayordomo JI, Larrad L, Ibarra MR, Tres A. Dendritic cell uptake of iron-based magnetic nanoparticles. Cell Biol Int 2008; 32:1001-5. [PMID: 18534870 DOI: 10.1016/j.cellbi.2008.04.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 04/01/2008] [Indexed: 11/30/2022]
Abstract
We have investigated the internalization of magnetic nanoparticles (NPs) into dendritic cells (DCs) in order to assess both the final location of the particles and the viability of the cultured cells. The particles, consisting of a metallic iron core covered with carbon, showed no toxic effects on the DCs and had no effect in their viability. We found that mature DCs are able to incorporate magnetic nanoparticles in a range of size from 10 nm to ca. 200 nm, after 24 h of incubation. We describe a method to separate cells loaded with NPs, and analyze the resulting material by electron microscopy and magnetic measurements. It is found that NPs are internalized in lysosomes, providing a large magnetic signal. Our results suggest that loading DCs with properly functionalized magnetic NPs could be a promising strategy for improved vectorization in cancer diagnosis and treatment.
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Affiliation(s)
- G F Goya
- Aragon Institute of Nanoscience (INA), University of Zaragoza, and Hospital Universitario Lozano Blesa, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
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21
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González-Melendi P, Fernández-Pacheco R, Coronado MJ, Corredor E, Testillano PS, Risueño MC, Marquina C, Ibarra MR, Rubiales D, Pérez-de-Luque A. Nanoparticles as smart treatment-delivery systems in plants: assessment of different techniques of microscopy for their visualization in plant tissues. Ann Bot 2008; 101:187-95. [PMID: 17998213 PMCID: PMC2701844 DOI: 10.1093/aob/mcm283] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 09/03/2007] [Accepted: 09/20/2007] [Indexed: 05/18/2023]
Abstract
BACKGROUND AND AIMS The great potential of using nanodevices as delivery systems to specific targets in living organisms was first explored for medical uses. In plants, the same principles can be applied for a broad range of uses, in particular to tackle infections. Nanoparticles tagged to agrochemicals or other substances could reduce the damage to other plant tissues and the amount of chemicals released into the environment. To explore the benefits of applying nanotechnology to agriculture, the first stage is to work out the correct penetration and transport of the nanoparticles into plants. This research is aimed (a) to put forward a number of tools for the detection and analysis of core-shell magnetic nanoparticles introduced into plants and (b) to assess the use of such magnetic nanoparticles for their concentration in selected plant tissues by magnetic field gradients. METHODS Cucurbita pepo plants were cultivated in vitro and treated with carbon-coated Fe nanoparticles. Different microscopy techniques were used for the detection and analysis of these magnetic nanoparticles, ranging from conventional light microscopy to confocal and electron microscopy. KEY RESULTS Penetration and translocation of magnetic nanoparticles in whole living plants and into plant cells were determined. The magnetic character allowed nanoparticles to be positioned in the desired plant tissue by applying a magnetic field gradient there; also the graphitic shell made good visualization possible using different microscopy techniques. CONCLUSIONS The results open a wide range of possibilities for using magnetic nanoparticles in general plant research and agronomy. The nanoparticles can be charged with different substances, introduced within the plants and, if necessary, concentrated into localized areas by using magnets. Also simple or more complex microscopical techniques can be used in localization studies.
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Affiliation(s)
- P. González-Melendi
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - R. Fernández-Pacheco
- Instituto de Nanociencia de Aragón, Universidad de Zaragoza, Edificio Interfacultativo II, Pedro Cerbuna 12, 50009-Zaragoza, Spain
| | - M. J. Coronado
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - E. Corredor
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - P. S. Testillano
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - M. C. Risueño
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - C. Marquina
- Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, E-28040 Madrid, Spain
| | - M. R. Ibarra
- Instituto de Nanociencia de Aragón, Universidad de Zaragoza, Edificio Interfacultativo II, Pedro Cerbuna 12, 50009-Zaragoza, Spain
- Instituto de Ciencia de Materiales de Aragón-Departamento de Física de la Materia Condensada, CSIC-Unversidad de Zaragoza, Pedro Cerbuna 12, 50009-Zaragoza, Spain
| | - D. Rubiales
- CSIC, Instituto de Agricultura Sostenible, Alameda del Obispo s/n, Apdo. 4084, E-14080 Córdoba, Spain
| | - A. Pérez-de-Luque
- CSIC, Instituto de Agricultura Sostenible, Alameda del Obispo s/n, Apdo. 4084, E-14080 Córdoba, Spain
- For correspondence. E-mail
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Magen C, Algarabel PA, Morellon L, Araújo JP, Ritter C, Ibarra MR, Pereira AM, Sousa JB. Observation of a Griffiths-like phase in the magnetocaloric compound Tb5Si2Ge2. Phys Rev Lett 2006; 96:167201. [PMID: 16712265 DOI: 10.1103/physrevlett.96.167201] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2005] [Indexed: 05/09/2023]
Abstract
The onset of a Griffiths-like phase has been observed in Tb5Si2Ge2 (TC=110 K) by means of magnetic susceptibility and small-angle neutron scattering experiments. We show the growth of a ferromagnetic cluster system characterized by an inverse susceptibility exponent lower than unity at TC<T<TG approximately 200 K. We suggest that the Griffiths-like state is originated by local disorder within the crystallographic structure, stabilized and enhanced by competing intralayer and interlayer magnetic interactions. Both factors thus promote segregation of nanometric regions with ferromagnetic interactions.
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Affiliation(s)
- C Magen
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza, Spain
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Fernández-Pacheco R, Ibarra MR, Valdivia JG, Marquina C, Serrate D, Romero MS, Gutiérrez M, Arbiol J. Carbon coated magnetic nanoparticles for local drug delivery using magnetic implants. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/s12030-005-0051-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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De Teresa JM, Algarabel PA, Ritter C, Blasco J, Ibarra MR, Morellon L, Espeso JI, Gómez-Sal JC. Possible quantum critical point in La(2/3)Ca(1/3)Mn(1-x)Ga x O3. Phys Rev Lett 2005; 94:207205. [PMID: 16090281 DOI: 10.1103/physrevlett.94.207205] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Indexed: 05/03/2023]
Abstract
We study the magnetic ground state in La(2/3)Ca(1/3)Mn(1-x)Ga x O3 manganites, where a quantum critical point (QCP) has been theoretically predicted. The metallic ferromagnetic ground state for low Ga doping breaks down for x > or = 0.11, an insulating state being established at low temperatures. Long-range ferromagnetism coexists with short-range magnetic correlations in the concentration range 0.11 < or = x < or = 0.145 while only the short-range correlations survive for x > or = 0.16. We discuss the implications of such a QCP to the physics of manganites and compare to other QCP systems.
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Affiliation(s)
- J M De Teresa
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Zaragoza, Spain.
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25
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Morellon L, Arnold Z, Magen C, Ritter C, Prokhnenko O, Skorokhod Y, Algarabel PA, Ibarra MR, Kamarad J. Pressure enhancement of the giant magnetocaloric effect in Tb5Si2Ge2. Phys Rev Lett 2004; 93:137201. [PMID: 15524753 DOI: 10.1103/physrevlett.93.137201] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Indexed: 05/24/2023]
Abstract
Effects of temperature and pressure on magnetic, elastic, structural, and thermal properties of Tb5Si2Ge2 have been studied by means of macroscopic (thermal expansion and magnetization) and microscopic (neutron powder diffraction) techniques. We present evidence that the high-temperature second-order ferromagnetic transition can be coupled with the low-temperature first-order structural phase change into a single first-order magnetic-crystallographic transformation at and above a tricritical point in the vicinity of 8.6 kbar. This pressure-induced coupling has a remarkable effect on the magnetocaloric effect, transforming Tb5Si2Ge2 from an ordinary into a giant magnetocaloric effect material.
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Affiliation(s)
- L Morellon
- Departamento de Física de la Materia Condensada and Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza, Spain.
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26
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Magen C, Arnold Z, Morellon L, Skorokhod Y, Algarabel PA, Ibarra MR, Kamarad J. Pressure-induced three-dimensional ferromagnetic correlations in the giant magnetocaloric compound Gd5Ge4. Phys Rev Lett 2003; 91:207202. [PMID: 14683388 DOI: 10.1103/physrevlett.91.207202] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Indexed: 05/24/2023]
Abstract
The giant magnetocaloric compound Gd5Ge4 is the only member of the Gd5(SixGe1-x)4 family where three-dimensional exchange interactions between two-dimensional correlated layers of the crystallographic structure are so weak that spontaneous ferromagnetism does not set in at any temperature. In this Letter we explore the possibility to reach the ferromagnetic state by application of hydrostatic pressure. Linear thermal expansion and magnetic measurements under pressure reveal that the reduction of the unit cell volume induces a spatially phase-segregated ground state below 10 kbar.
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Affiliation(s)
- C Magen
- Departamento de Física de la Materia Condensada and Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza, Spain
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Ibarra MR, Moze O, Algarabel PA, Arnaudas JI, Abell JS, Moral AD. Magnetoelastic behaviour and the spin-reorientation transition in HoAl2. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3719/21/14/013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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29
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Kapusta C, Riedi PC, Sikora M, Ibarra MR. NMR probe of phase segregation in electron doped mixed valence manganites. Phys Rev Lett 2000; 84:4216-4219. [PMID: 10990649 DOI: 10.1103/physrevlett.84.4216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/1999] [Indexed: 05/23/2023]
Abstract
A 55Mn and 139La NMR study of La0.35Ca0.65MnO3 is reported. The zero field 55Mn spectra consist of two lines centered at 290 and 375 MHz. Their behavior under an applied magnetic field makes it possible to attribute them to regions of antiferromagnetically and ferromagnetically coupled Mn spins, respectively. This gives evidence for the existence of electronic phase segregation of microscopic ferromagnetic regions of double exchange coupled Mn spins over a charge ordered antiferromagnetic background. The behavior of these ferromagnetic regions in the applied magnetic field is related to the magnetoresistive properties of the manganites.
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Affiliation(s)
- C Kapusta
- Department of Solid State Physics, Faculty of Physics and Nuclear Techniques, University of Mining and Metallurgy, 30-059 Cracow, Poland and and Department of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife, KY16 9SS, Scotlan
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30
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Garcia-Landa B, Marquina C, Ibarra MR, Balakrishnan G, Lees MR, McK Paul D. Volume and anisotropic spontaneous striction in layered manganites: role of charge localization and magnetic interactions. Phys Rev Lett 2000; 84:995-998. [PMID: 11017424 DOI: 10.1103/physrevlett.84.995] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/1999] [Indexed: 05/23/2023]
Abstract
Thermal expansion measurements have been performed on single crystals of R2-2xSr1+2xMn2O7 (R=Pr, Nd, and Dy) over a wide temperature range (4-900 K). Our analysis allows us to give a general explanation for the large lattice anomalies observed in the layered manganites. Localization of the carriers gives rise to volume and anisotropic anomalies in the paramagnetic regime. The anisotropic distortion is enhanced with the establishment of long-range antiferromagnetism, whereas it is quenched by long-range ferromagnetic order.
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Affiliation(s)
- B Garcia-Landa
- Departamento de Fisica de la Materia Condensada and Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza and Consejo Superior de Investigaciones Cientificas, Facultad de Ciencias, 50009 Zaragoza, Spain
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Ibarra MR, Marquina C, Algarabel PA, Oseroff S. Crossover from charge-localized state to charge-ordered state in Pr2/3Ca1/3MnO3. Phys Rev B Condens Matter 1996; 54:R12689-R12692. [PMID: 9985220 DOI: 10.1103/physrevb.54.r12689] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ibarra MR, Blasco J, García J, Marquina C, Algarabel PA, Arnold Z, Kamenev K, Ritter C. Spontaneous behavior and magnetic field and pressure effects on La2/3Ca1/3MnO3 perovskite. Phys Rev B Condens Matter 1996; 54:1187-1193. [PMID: 9985389 DOI: 10.1103/physrevb.54.1187] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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33
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Ibarra MR, García J, Blasco J, Ritter C, Algarabel PA, Marquina C. Spin-glass insulator state in (Tb-La)2/3Ca1/3MnO3 perovskite. Phys Rev Lett 1996; 76:3392-3395. [PMID: 10060955 DOI: 10.1103/physrevlett.76.3392] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Ibarra MR, Algarabel PA, Marquina C, Blasco J, García J. Large magnetovolume effect in yttrium doped La-Ca-Mn-O perovskite. Phys Rev Lett 1995; 75:3541-3544. [PMID: 10059612 DOI: 10.1103/physrevlett.75.3541] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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35
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Adroja DT, Rainford BD, Ibarra MR, Knight KS. First-order valence phase transition in CeNi1-xCoxSn alloys. Phys Rev B Condens Matter 1995; 52:12790-12797. [PMID: 9980446 DOI: 10.1103/physrevb.52.12790] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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36
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Chaboy J, Ibarra MR. X-ray-absorption spectroscopy investigation of the martensitic structural transformation in the RCu (R=rare earth) series. Phys Rev B Condens Matter 1995; 52:3206-3213. [PMID: 9981437 DOI: 10.1103/physrevb.52.3206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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37
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García-Landa B, Ibarra MR, Algarabel PA, Moze O. Crystal-electric-field interaction in R2Zn17 intermetallics. Phys Rev B Condens Matter 1995; 51:15132-15145. [PMID: 9978467 DOI: 10.1103/physrevb.51.15132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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38
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Nagamine LC, Rechenberg HR, Algarabel PA, Ibarra MR. Magnetic phase diagram of (DyxGd1-x)Fe11Ti alloys. Phys Rev B Condens Matter 1994; 50:12659-12664. [PMID: 9975429 DOI: 10.1103/physrevb.50.12659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ibarra MR, Morellon L, Algarabel PA, Moze O. Single-ion competing magnetic anisotropies in PrxNd1-xCo5 intermetallic compounds. Phys Rev B Condens Matter 1991; 44:9368-9377. [PMID: 9998918 DOI: 10.1103/physrevb.44.9368] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ibarra MR, Marquina C, Arnaudas JI, Algarabel PA. Critical behavior in spin-reorientation phase transitions: (ErxR1-x)2Fe14B (R=Nd, Dy) magnets. Phys Rev B Condens Matter 1989; 40:7192-7198. [PMID: 9991106 DOI: 10.1103/physrevb.40.7192] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ibarra MR, Algarabel PA, Marquina C, Arnaudas JI, Pareti L, Moze O, Marusi G, Solzi M. Magnetic phase diagram and anisotropy of pseudoternary (ErxDy1-x)2Fe14B compounds. Phys Rev B Condens Matter 1989; 39:7081-7088. [PMID: 9947357 DOI: 10.1103/physrevb.39.7081] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ibarra MR, Abell JS, Montenegro JF. Anisotropy in the paramagnetic phase of RAl2 cubic intermetallic compounds (R=Tb, Dy, and Er). Phys Rev B Condens Matter 1987; 35:6800-6807. [PMID: 9940932 DOI: 10.1103/physrevb.35.6800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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