201
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Ferrando R, Jellinek J, Johnston RL. Nanoalloys: From Theory to Applications of Alloy Clusters and Nanoparticles. Chem Rev 2008; 108:845-910. [PMID: 18335972 DOI: 10.1021/cr040090g] [Citation(s) in RCA: 1716] [Impact Index Per Article: 107.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Riccardo Ferrando
- Dipartimento di Fisica, Universita di Genova, INFM and IMEM/CNR, Via Dodecaneso 33, Genova, I16146, Italy, Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, and School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Julius Jellinek
- Dipartimento di Fisica, Universita di Genova, INFM and IMEM/CNR, Via Dodecaneso 33, Genova, I16146, Italy, Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, and School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Roy L. Johnston
- Dipartimento di Fisica, Universita di Genova, INFM and IMEM/CNR, Via Dodecaneso 33, Genova, I16146, Italy, Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, and School of Chemistry, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
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202
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Theoretical study on the spin states and intra-cluster spin relaxation of the one-dimensional metal–benzene sandwich clusters: M2(C6H6)3 (M=Sc, Ti, V). Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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203
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Gruner ME, Rollmann G, Entel P, Farle M. Multiply twinned morphologies of FePt and CoPt nanoparticles. PHYSICAL REVIEW LETTERS 2008; 100:087203. [PMID: 18352659 DOI: 10.1103/physrevlett.100.087203] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Indexed: 05/26/2023]
Abstract
Based on large-scale density functional theory calculations we provide a systematic overview of the size dependence of the energetic order and magnetic properties of various morphologies of FePt and CoPt clusters with diameters of up to 2.5 nm. For FePt, ordered multiply twinned icosahedra and decahedra are more favorable than the L1_(0) phase throughout the investigated size range. For CoPt, segregated morphologies predominate with considerably increased energy differences to the L1_(0) structure. The compositional trends are traced back to differences between the morphologies in the partial electronic density of states associated with the 3d element.
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Affiliation(s)
- Markus E Gruner
- Physics Department , University of Duisburg-Essen, 47048 Duisburg, Germany
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204
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Miyajima K, Knickelbein MB, Nakajima A. Stern-gerlach study of multidecker lanthanide-cyclooctatetraene sandwich clusters. J Phys Chem A 2008; 112:366-75. [PMID: 18166028 DOI: 10.1021/jp0766196] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Multilayer lanthanide-cyclooctatetraene organometallic clusters, Lnn(C8H8)m (Ln = Eu, Tb, Ho, Tm; n = 1-7; m = n - 1, n, n + 1) were produced by a laser vaporization synthesis method. The magnetic deflections of these organometallic sandwich clusters were measured by a molecular beam magnetic deflection technique. Most of the sandwich species displayed one-sided deflection, while some of smaller Ln-C8H8 clusters showed symmetric broadening without or with only very small (or absent) net high-field deflection. In general, the total magnetic moments, calculated from the magnitude of the beams deflections, increase with the number of lanthanide atoms (i.e., with increasing sandwich layers); however for Tb-, Ho-, and Tm-C8H8 clusters with n > 3, the suppression of the magnetic moments was observed, possibly through antiferromagnetic interactions. For Eu-C8H8 clusters, we observe a linear increase of the magnetic moments with the number of Eu atoms up to n = 7, with average magnetic moment per Eu atom around 7 muB--similar to that displayed by conventionally synthesized mononuclear EuIIC8H8 complexes, indicating that Eu atoms exist as Eu2+ ions in the full sandwich Eun(C8H8)n+1 clusters. These results suggest that Eun(C8H8)n+1 is a promising candidate for a high-spin, one-dimensional building block in organometallic magnetic materials.
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Affiliation(s)
- Ken Miyajima
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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205
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Muñoz-Navia M, Dorantes-Dávila J, Zitoun D, Amiens C, Chaudret B, Casanove MJ, Lecante P, Jaouen N, Rogalev A, Respaud M, Pastor GM. Magnetic properties of CoNRhMnanoparticles: experiment and theory. Faraday Discuss 2008; 138:181-92; discussion 211-23, 433-4. [DOI: 10.1039/b705122k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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206
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Casu A, Casula MF, Corrias A, Falqui A, Loche D, Marras S, Sangregorio C. The influence of composition and porosity on the magnetic properties of FeCo–SiO2nanocomposite aerogels. Phys Chem Chem Phys 2008; 10:1043-52. [DOI: 10.1039/b712719g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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207
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Fernández-Seivane L, Ferrer J. Magnetic anisotropies of late transition metal atomic clusters. PHYSICAL REVIEW LETTERS 2007; 99:183401. [PMID: 17995405 DOI: 10.1103/physrevlett.99.183401] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Indexed: 05/25/2023]
Abstract
We analyze the impact of the magnetic anisotropy on the geometric structure and magnetic ordering of small atomic clusters of palladium, iridium, platinum, and gold. We have employed a noncollinear implementation of density functional theory where the spin-orbit interaction has been included self-consistently. The size of the clusters ranges from two to five, six, or seven atoms, depending on the element. Our results highlight the relevance of the spin-orbit interaction in the magnetic properties of small atomic clusters made of fourth- and fifth-row elements.
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208
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Stevanović V, Sljivancanin Z, Baldereschi A. Effect of carbon adsorption on the isomer stability of Ir4 clusters. PHYSICAL REVIEW LETTERS 2007; 99:165501. [PMID: 17995263 DOI: 10.1103/physrevlett.99.165501] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Indexed: 05/25/2023]
Abstract
The atomic structure and electronic properties of gas-phase and MgO100-supported iridium tetramers are studied using density functional theory. At variance with experimental data, the most stable Ir4 isomer on MgO100 is the square one, as in the gas phase, and the metastable tetrahedral isomer is highly distorted by interactions with the substrate. In the presence of a single carbon adatom, the most stable structure of Ir4 is tetrahedral for both environments and the structural distortion of the adsorbed cluster is reduced. On MgO100, the binding energy of a C adatom to tetrahedral Ir4 is 1.6 eV larger than that to the square isomer, due to strong interactions between C-2p orbitals and a low-energy unoccupied molecular orbital of tetrahedral Ir4.
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Affiliation(s)
- Vladan Stevanović
- Institute of Theoretical Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH - 1015 Lausanne, Switzerland
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209
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Suzdalev IP, Suzdalev PI. Nanoclusters and nanocluster systems. Assembling, interactions and properties. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc2001v070n03abeh000627] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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210
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Luo W, Pennycook SJ, Pantelides ST. s-Electron ferromagnetism in gold and silver nanoclusters. NANO LETTERS 2007; 7:3134-7. [PMID: 17867717 DOI: 10.1021/nl071688h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Ferromagnetic (FM) ordering in transition-metal systems (solids, surface layers, nanoparticles) arises from partially filled d shells. Thus, recent observations of FM Au nanoclusters was unexpected, and an explanation has remained elusive. Here we report first-principles density-functional spin-polarized calculations for Au and Ag nanoclusters. We find that the highest-occupied level is highly degenerate and partially filled by s electrons with spins aligned according to Hund's rule. The nanoclusters behave like "superatoms", with the spin-aligned electrons being itinerant on the outer shell of atoms.
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Affiliation(s)
- Weidong Luo
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
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211
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212
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Strandberg TO, Canali CM, MacDonald AH. Transition-metal dimers and physical limits on magnetic anisotropy. NATURE MATERIALS 2007; 6:648-51. [PMID: 17660824 DOI: 10.1038/nmat1968] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 06/21/2007] [Indexed: 05/16/2023]
Abstract
Recent advances in nanoscience have raised interest in the minimum bit size required for classical information storage. This bit size is determined by the necessity for bistability with suppressed quantum tunnelling and energy barriers that exceed ambient temperatures. In the case of magnetic information storage, much attention has centred on molecular magnets with bits consisting of about 100 atoms, magnetic uniaxial anisotropy energy barriers of about 50 K and very slow relaxation at low temperatures. Here, we draw attention to the remarkable magnetic properties of some transition-metal dimers, which have energy barriers approaching 500 K with only two atoms. The spin dynamics of these ultrasmall nanomagnets is strongly affected by a Berry phase, which arises from quasi-degeneracies at the electronic highest occupied molecular orbital energy. In a giant-spin approximation, this Berry phase makes the effective reversal barrier thicker.
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Affiliation(s)
- Tor O Strandberg
- Division of Physics, Department of Natural Sciences, Kalmar University, S31912 Kalmar, Sweden.
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213
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Rollmann G, Gruner ME, Hucht A, Meyer R, Entel P, Tiago ML, Chelikowsky JR. Shellwise Mackay transformation in iron nanoclusters. PHYSICAL REVIEW LETTERS 2007; 99:083402. [PMID: 17930948 DOI: 10.1103/physrevlett.99.083402] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2006] [Indexed: 05/25/2023]
Abstract
Structure and magnetism of iron clusters with up to 641 atoms have been investigated by means of density functional theory calculations including full geometric optimizations. Body-centered cubic (bcc) isomers are found to be lowest in energy when the clusters contain more than about 100 atoms. In addition, another stable conformation has been identified for magic-number clusters, which lies well within the range of thermal energies as compared to the bcc isomers. Its structure is characterized by a close-packed particle core and an icosahedral surface, while intermediate shells are partially transformed along the Mackay path between icosahedral and cuboctahedral geometry. The gradual transformation results in a favorable bcc environment for the subsurface atoms. For Fe55, the shellwise Mackay-transformed morphology is a promising candidate for the ground state.
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Affiliation(s)
- Georg Rollmann
- Physics Department, University of Duisburg-Essen, 47048, Duisburg, Germany
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214
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Knickelbein MB. Magnetic moments of bare and benzene-capped cobalt clusters. J Chem Phys 2007; 125:44308. [PMID: 16942143 DOI: 10.1063/1.2217951] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Magnetic moments of bare cobalt clusters Co(n) (n=7-32) and benzene-capped cobalt clusters Co(n)(bz)(m) have been measured at temperatures ranging from 54 to 150 K using a molecular beam deflection method. It was observed that Co(12-32) produced at temperatures greater than approximately 100 K display high-field-seeking behavior at all temperatures in the range investigated, indicating that they are superparamagnetic species. At temperatures below approximately 100 K, the field-on beam profiles of Co(7-11) and some larger clusters displayed substantial symmetric broadening, indicating that some fraction of the clusters in the beam were no longer superparamagnetic, but rather were in a blocked (locked-moment) state. In the superparamagnetic regime (T=150 K) Co(n) clusters in the n=7-32 size range were found to possess per-atom moments ranging from 1.96+/-0.04 micro(b)(Co(24)) to 2.53+/-0.04 micro(b)(Co(16)), significantly above the bulk value of 1.72 micro(b). Locked-moment isomers were found to display moments of approximately 1 micro(b) per atom. Cobalt clusters containing a layer of adsorbed benzene molecules were found to possess significantly lower moments per cobalt atom than the corresponding bare cobalt clusters.
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Affiliation(s)
- Mark B Knickelbein
- Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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215
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Yin S, Moro R, Xu X, de Heer WA. Magnetic enhancement in cobalt-manganese alloy clusters. PHYSICAL REVIEW LETTERS 2007; 98:113401. [PMID: 17501052 DOI: 10.1103/physrevlett.98.113401] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Indexed: 05/15/2023]
Abstract
Magnetic moments of Co(N)Mn(M) and Co(N)V(M) clusters (N < or = 60; M < or = N/3) are measured in molecular beams using the Stern-Gerlach deflection method. Surprisingly, the per atom average moments of Co(N)Mn(M) clusters are found to increase with Mn concentration, in contrast to bulk CoMn. The enhancement with Mn doping is found to be independent of cluster size and composition in the size range studied. Meanwhile, Co(N)V(M) clusters show reduction of average moments with increasing V doping, consistent with what is expected in bulk CoV. The results are discussed within the virtual bound states model.
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Affiliation(s)
- Shuangye Yin
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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216
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Abstract
The static electric dipole polarizabilities of rhodium clusters Rhn, n=5-28, have been measured via a molecular beam deflection method. Uniform high-field beam deflections, indicative of induced polarization, were observed for all Rhn except Rh7 and Rh10 which by contrast exhibited beam broadening and anomalously high effective polarizabilities. Analysis of the beam deflection profile of Rh7 indicates that it possesses a permanent dipole moment of 0.24+/-0.02 D. Unlike the other clusters in the n=5-28 size range, the polarizability of Rh10 is observed to decrease with increasing source temperature. We attribute this temperature dependence to paraelectric behavior, suggesting that Rh10 is a fluxional molecule possessing a dipole moment that spatially fluctuates, uncorrelated with overall rotation.
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Affiliation(s)
- Martin K Beyer
- Institut für Chemie, Sekr. C4, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
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217
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218
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219
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Liu X, Bauer M, Bertagnolli H, Roduner E, van Slageren J, Phillipp F. Structure and magnetization of small monodisperse platinum clusters. PHYSICAL REVIEW LETTERS 2006; 97:253401. [PMID: 17280350 DOI: 10.1103/physrevlett.97.253401] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2006] [Indexed: 05/13/2023]
Abstract
Magnetization measurements of well-characterized monodisperse Pt clusters consisting of 13+/-2 atoms in a zeolite confirm the predicted extraordinary magnetic polarization with up to 8 unpaired electrons on a cluster, corresponding to a magnetic moment of 0.65(5) microB per atom. The effect is partly quenched by hydrogen chemisorption. The study provides insight into the electronic structure of the cluster and is fundamental for an understanding of how magnetism develops in small clusters.
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Affiliation(s)
- Xiong Liu
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany
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220
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Gutsev GL, Mochena MD, Johnson E, Bauschlicher CW. Dissociative and associative attachment of NO to iron clusters. J Chem Phys 2006; 125:194312. [PMID: 17129108 DOI: 10.1063/1.2378831] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Electronic and geometrical structures of iron clusters with associative (FeNO, Fe2NO, Fe3NO, Fe4NO, Fe5NO, and Fe6NO) and dissociative (OFeN, OFe2N, OFe3N, OFe4N, OFe5N, and OFe6N) attachments of NO, as well as the corresponding singly negatively and positively charged ions, are computed using density functional theory with generalized gradient corrections. Both types of isomers are found to be stable and no spontaneous dissociation was observed during the geometry optimizations. The ground states correspond to dissociative attachment of NO for all iron clusters Fe(n), except for Fe and Fe+. All of the OFe(n)N clusters have ferrimagnetic ground states, except for OFe2N, OFe2N-, OFe4N, and OFe4N-, which prefer the ferromagnetic coupling. In the ferrimagnetic states, the excess spin density at one iron atom couples antiferromagnetically to the excess spin densities of all other iron atoms. Relative to the high-spin Fe(n) ground state, the lowest energy ferrimagnetic state quenches the total magnetic moments of iron clusters by 7, which is to be compared with a reduction in the magnetic moment of one in the lowest energy ferromagnetic states. Dissociation of NO on the iron clusters has a pronounced impact on the energetics of reactions; the Fe(n)NO+CO-->Fe(n)N+CO2 channels are exothermic while the OFe6N+CO--> Fe6N+CO2 channels are nearly thermoneutral.
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Affiliation(s)
- G L Gutsev
- Department of Physics, Florida A&M University, Tallahassee, Florida 32307, USA.
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221
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Payne FW, Jiang W, Bloomfield LA. Magnetism and magnetic isomers in free chromium clusters. PHYSICAL REVIEW LETTERS 2006; 97:193401. [PMID: 17155626 DOI: 10.1103/physrevlett.97.193401] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Indexed: 05/12/2023]
Abstract
We have used the Stern-Gerlach deflection technique to study magnetism in chromium clusters of 20-133 atoms at temperatures between 60 and 100 K. We observe that these clusters have large magnetic moments and respond superparamagnetically to applied magnetic fields. Using superparamagnetic theory, we have determined the moment per atom for each cluster size and find that it often far exceeds the moment per atom present anywhere in the bulk antiferromagnetic lattice. Remarkably, our cluster beam contains two magnetically distinguishable forms of each cluster size with > or =34 atoms. We attribute this observation to structural isomers.
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Affiliation(s)
- F W Payne
- Department of Physics, University of Virginia, Charlottesville, VA 22904, USA
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222
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Tiago ML, Zhou Y, Alemany MMG, Saad Y, Chelikowsky JR. Evolution of magnetism in iron from the atom to the bulk. PHYSICAL REVIEW LETTERS 2006; 97:147201. [PMID: 17155287 DOI: 10.1103/physrevlett.97.147201] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Indexed: 05/12/2023]
Abstract
The evolution of the magnetic moment in iron clusters containing 20-400 atoms is investigated using first-principles numerical calculations based on density-functional theory and real-space pseudopotentials. Three families of clusters are studied, characterized by the arrangement of atoms: icosahedral, body-centered cubic centered on an atom site, and body-centered cubic centered on the bridge between two neighboring atoms. We find an overall decrease of magnetic moment as the clusters grow in size towards the bulk limit. Clusters with faceted surfaces are predicted to have magnetic moment lower than other clusters with similar size. As a result, the magnetic moment is observed to decrease as function of size in a nonmonotonic manner, which explains measurements performed at low temperatures.
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Affiliation(s)
- Murilo L Tiago
- Center for Computational Materials, Institute for Computational Engineering and Sciences, University of Texas, Austin, Texas 78712, USA
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223
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Jena P, Castleman AW. Clusters: a bridge across the disciplines of physics and chemistry. Proc Natl Acad Sci U S A 2006; 103:10560-9. [PMID: 16835306 PMCID: PMC1636021 DOI: 10.1073/pnas.0601782103] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Puru Jena
- *Department of Physics, Virginia Commonwealth University, Richmond, VA 23284; and
- To whom correspondence may be addressed. E-mail:
or
| | - A. W. Castleman
- Departments of Chemistry and Physics, Pennsylvania State University, University Park, PA 16802
- To whom correspondence may be addressed. E-mail:
or
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224
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Conus F, Rodrigues V, Lecoultre S, Rydlo A, Félix C. Matrix effects on the optical response of silver nanoclusters. J Chem Phys 2006; 125:24511. [PMID: 16848596 DOI: 10.1063/1.2219442] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We report absorption spectra for Ag(7), Ag(9), and Ag(11) in an argon matrix grown at a temperature of 28 K and compare them with previous spectra of the same species measured in matrices of argon grown at lower temperatures as well as in neon matrices. We discuss the discrepancies in the light of the matrix crystallinity and show that this leads to an understanding of the influence of the matrix on the optical response of small clusters.
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Affiliation(s)
- F Conus
- Institut de Physique des Nanostructures, EPFL, CH-1015 Lausanne, Switzerland
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225
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Reboredo FA, Galli G. Size and Structure Dependence of Carbon Monoxide Chemisorption on Cobalt Clusters. J Phys Chem B 2006; 110:7979-84. [PMID: 16610897 DOI: 10.1021/jp056291l] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have carried out a series of ab initio calculations to investigate changes in the structural and magnetic properties of pristine cobalt clusters upon CO chemisorption. Our results show that binding energies of CO to 13-55 atom (0.5-1.5 nm) cobalt nanoparticles and preferred chemisorption sites depend on the cluster structure (whether fcc or icosahedral), size, and surface coverage. In addition, we find a strong influence of CO on the magnetism of the cluster, leading to magnetic moments smaller than in the bulk, at variance with pristine clusters which have magnetic moments larger than the bulk. Our findings suggest important changes in catalytic properties of cobalt at the nanoscale. Our theory suggests that at the nanoscale cluster size and surface coverage might control catalysis.
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226
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Douglas Edmonds B, Kandalam AK, Khanna SN, Li X, Grubisic A, Khanna I, Bowen KH. Structure and stability of Con(pyridine)m− clusters: Absence of metal inserted structures. J Chem Phys 2006; 124:74316. [PMID: 16497045 DOI: 10.1063/1.2164455] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A synergistic approach combining the experimental photoelectron spectroscopy and theoretical electronic structure studies is used to probe the geometrical structure and the spin magnetic moment of Co(n)(pyridine)(m) (-) clusters. It is predicted that the ground state of Co(pyridine)(-) is a structure where the Co atom is inserted in a CH bond. However, the insertion is marked by a barrier of 0.33 eV that is not overcome under the existing experimental conditions resulting in the formation of a structure where Co occupies a site above the pyridine plane. For Co(2)(pyridine)(-), a ground-state structure is predicted in which the Co(2) diametric moiety is inserted in one of the CH bonds, but again because of a barrier, the structure which matches the photoelectron spectrum is a higher-energy isomer in which the Co(2) moiety is bonded directly to nitrogen on the pyridine ring. In all cases, the Co sites have finite magnetic moments suggesting that the complexes may provide ways of making cluster-based magnetic materials.
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Affiliation(s)
- B Douglas Edmonds
- Physics Department, Virginia Commonwealth University, Richmond, 23284-2000, USA
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227
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Guo Z, Pereira T, Choi O, Wang Y, Hahn HT. Surface functionalized alumina nanoparticle filled polymeric nanocomposites with enhanced mechanical properties. ACTA ACUST UNITED AC 2006. [DOI: 10.1039/b603020c] [Citation(s) in RCA: 307] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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228
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Schweyer-Tihay F, Estournès C, Braunstein P, Guille J, Paillaud JL, Richard-Plouet M, Rosé J. On the nature of metallic nanoparticles obtained from molecular Co3Ru–carbonyl clusters in mesoporous silica matrices. Phys Chem Chem Phys 2006; 8:4018-28. [PMID: 17028692 DOI: 10.1039/b603404g] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on the impregnation of THF solutions of the low-valent heterometallic cluster NEt(4)[Co(3)Ru(CO)(12)] into two mesoporous silica matrices, amorphous xerogels and ordered MCM-41, and a study of its thermal decomposition into metallic nanoparticles by X-ray diffraction, transmission electron microscopy and in situ magnetic measurements under controlled atmospheres. The decomposition of the cluster was monitored as a function of temperature by examining the chemical composition of the particles, their size distributions and their structures as well as their magnetic properties. Treatment under inert atmosphere (i.e. argon) at temperatures below 200 degrees C resulted in the formation of segregated spherical particles of hcp-ruthenium (2.3 +/- 1.0 nm) and hcp-cobalt (3.1 +/- 0.9 nm). The latter is transformed to fcc-cobalt (3.2 +/- 1.0 nm) above 270 degrees C. At higher temperatures, Co-Ru alloying takes place and the Ru content of the particles increases with increasing temperature to reach the nominal composition of the molecular precursor, Co(3)Ru. The particles are more evenly distributed in the MCM-41 framework compared to the disordered xerogel and also show a narrower size distribution. Owing to the different magnetic anisotropy of hcp- and fcc-cobalt, which results in different blocking temperatures, we were able to clearly identify the products formed at the early stages of the thermal decomposition procedure.
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Affiliation(s)
- Fanny Schweyer-Tihay
- Groupe des Matériaux Inorganiques, Institut de Physique et Chimie des Matériaux, UMR 7504 CNRS, 23 rue du Loess, 67037 Strasbourg Cedex, France
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229
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Li X, Kiran B, Cui LF, Wang LS. Magnetic properties in transition-metal-doped gold clusters: M@Au6 (M = Ti, V, Cr). PHYSICAL REVIEW LETTERS 2005; 95:253401. [PMID: 16386056 DOI: 10.1103/physrevlett.95.253401] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Indexed: 05/05/2023]
Abstract
The electronic structure and magnetic properties in a series of transition-metal-doped Au clusters, MAu6- (M = Ti, V, Cr), are investigated experimentally using photoelectron spectroscopy (PES) and density functional calculations. PES features due to the impurity atoms and the host are clearly observed. It is found that all the MAu6- and MAu6 clusters possess a planar structure, in which the transition metal atom is located in the center of an Au6 ring and carries large magnetic moments (2, 3, and 4 muB for MAu6, M = Ti, V, and Cr, respectively).
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Affiliation(s)
- Xi Li
- Department of Physics, Washington State University, 2710 University Drive, Richland, Washington 99352, USA
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230
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Barea E, Batlle X, Bourges P, Corma A, Fornés V, Labarta A, Puntes VF. Synthesis and Characterization of Stabilized Subnanometric Cobalt Metal Particles. J Am Chem Soc 2005; 127:18026-30. [PMID: 16366553 DOI: 10.1021/ja053746b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Subnanometric cobalt metallic particles, with an average size of 0.8 nm and an estimated number of 50 atoms, have been stabilized in the confined spaces within the nanopores of crystalline molecular sieves. Remarkably, these clusters show a rapid vanishing of the magnetization as the temperature is increased from 10 to 20 K because of the ferromagnetic-paramagnetic transition together with thermal fluctuations of the remaining moment. This dramatic reduction of the transition temperature is due to strong finite size effects. Such behavior, predicted for very small metallic particles, was never observed before due to the inherent difficulty in achieving subnanometric stable metallic particles.
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Affiliation(s)
- Eva Barea
- Instituto de Tecnología Química, UPV-CSIC, Av. los Naranjos s/n, Valencia, Departament de Física Fonamental, Universitat de Barcelona, 647 Av Diagonal, 08028 Barcelona, Spain
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231
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Xu X, Yin S, Moro R, de Heer WA. Magnetic moments and adiabatic magnetization of free cobalt clusters. PHYSICAL REVIEW LETTERS 2005; 95:237209. [PMID: 16384341 DOI: 10.1103/physrevlett.95.237209] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Revised: 06/13/2005] [Indexed: 05/05/2023]
Abstract
Magnetizations and magnetic moments of free cobalt clusters Co(N) (12 < N < 200) in a cryogenic (25 K < or = T < or = 100 K) molecular beam were determined from Stern-Gerlach deflections. All clusters preferentially deflect in the direction of the increasing field and the average magnetization resembles the Langevin function for all cluster sizes even at low temperatures. We demonstrate in the avoided crossing model that the average magnetization may result from adiabatic processes of rotating and vibrating clusters in the magnetic field and that spin relaxation is not involved. This resolves a long-standing problem in the interpretation of cluster beam deflection experiments with implications for nanomagnetic systems in general.
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Affiliation(s)
- Xiaoshan Xu
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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232
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Bala T, Sankar CR, Baidakova M, Osipov V, Enoki T, Joy PA, Prasad BLV, Sastry M. Cobalt and magnesium ferrite nanoparticles: preparation using liquid foams as templates and their magnetic characteristics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:10638-43. [PMID: 16262331 DOI: 10.1021/la051595k] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
An easy and convenient method for the synthesis of cobalt and magnesium ferrite nanoparticles is demonstrated using liquid foams as templates. The foam is formed from an aqueous mixture of an anionic surfactant and the desired metal ions, where the metal ions are electrostatically entrapped by the surfactant at the thin borders between the foam bubbles and their junctions. The hydrolysis is carried out using alkali resulting in the formation of desired nanoparticles, with the foam playing the role of a template. However, in the formation of ferrites with the formula MFe(2)O(4), where the metal ion and iron possess oxidation states of +2 and +3, respectively, forming a foam from a 1:2 mixture of the desired ionic solutions would lead to a foam composition at variance with the original solution mixture because of greater electrostatic binding of ions possessing a greater charge with the surfactant. In our procedure, we circumvent this problem by preparing the foam from a 1:2 mixture of M(2+) and Fe(2+) ions and then utilizing the in situ conversion of Fe(2+) to Fe(3+) under basic conditions inside the foam matrix to get the desired composition of the metal ions with the required oxidation states. The fact that we could prepare both CoFe(2)O(4) and MgFe(2)O(4) particles shows the vast scope of this method for making even multicomponent oxides. The magnetic nanoparticles thus obtained exhibit a good crystalline nature and are characterized by superparamagnetic properties. The magnetic features observed for CoFe(2)O(4) and MgFe(2)O(4) nanoparticles are well in accordance with the expected behaviors, with CoFe(2)O(4) particles showing higher blocking temperatures and larger coercivities. These features can easily be explained by the contribution of Co(2+) sites to the magnetocrystalline anisotropy and the absence of the same from the Mg(2+) ions.
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Affiliation(s)
- Tanushree Bala
- Materials Chemistry Division, National Chemical Laboratory, Pune, India
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233
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Magnetic properties of lanthanide organometallic sandwich complexes produced in a molecular beam. Polyhedron 2005. [DOI: 10.1016/j.poly.2005.03.175] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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234
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Salgueiriño-Maceira V, Correa-Duarte MA, Farle M. Manipulation of chemically synthesized FePt nanoparticles in water: core-shell silica/FePt nanocomposites. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2005; 1:1073-6. [PMID: 17193398 DOI: 10.1002/smll.200500135] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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235
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236
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Weiss N, Cren T, Epple M, Rusponi S, Baudot G, Rohart S, Tejeda A, Repain V, Rousset S, Ohresser P, Scheurer F, Bencok P, Brune H. Uniform magnetic properties for an ultrahigh-density lattice of noninteracting co nanostructures. PHYSICAL REVIEW LETTERS 2005; 95:157204. [PMID: 16241757 DOI: 10.1103/physrevlett.95.157204] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Indexed: 05/05/2023]
Abstract
We report on the magnetic properties of two-dimensional Co nanoparticles arranged in macroscopically phase-coherent superlattices created by self-assembly on Au(788). Our particles have a density of 26 Tera/in2 (1 Tera=10(12)), are monodomain, and have uniaxial out-of-plane anisotropy. The distribution of the magnetic anisotropy energies has a half width at half maximum of 17%, a factor of 2 more narrow than the best results reported for superlattices of three-dimensional nanoparticles. Our data show the absence of magnetic interactions between the particles. Co/Au(788) thus constitutes an ideal model system to explore the ultimate density limit of magnetic recording.
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Affiliation(s)
- N Weiss
- Institut de Physique des Nanostructures, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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237
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Kim Y, Luzzi DE. Purification of Pulsed Laser Synthesized Single Wall Carbon Nanotubes by Magnetic Filtration. J Phys Chem B 2005; 109:16636-43. [PMID: 16853116 DOI: 10.1021/jp0522359] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Great effort has been expended in the development of methods to purify raw nanotubes by chemical treatment, washing, mechanical filtration, or heat treatment in a vacuum or oxidative environment. These techniques are limited by incomplete removal of catalyst nanoparticles and by the damage to the nanotubes that often results. We have applied a new purification method using filtration in a magnetic field and oxidation and investigated the efficacy using magnetic filtration alone, or combined with chemical-based or annealing-based oxidative treatments. By applying magnetic filtration only, we reduce catalyst content from 11.7 to 3.7 wt %, which is a superior result to oxidation and/or chemical treated samples. By combining chemical and magnetic purification, metal catalyst content is reduced to as much as 0.3 wt %, which is the best result ever for SWNTs synthesized by the laser method. In addition to the reduction of catalyst content, the new purification method increased sample quality, confirmed by Raman spectroscopy and near-infrared absorption. Magnetic filtration is found to be very effective in removing metal catalysts, producing material with high quality and yields.
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Affiliation(s)
- Younghyun Kim
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272, USA
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238
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Landman U. Materials by numbers: computations as tools of discovery. Proc Natl Acad Sci U S A 2005; 102:6671-8. [PMID: 15870210 PMCID: PMC1100739 DOI: 10.1073/pnas.0408038102] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Indexed: 11/18/2022] Open
Abstract
Current issues pertaining to theoretical simulations of materials, with a focus on systems of nanometer-scale dimensions, are discussed. The use of atomistic simulations as high-resolution numerical experiments, enabling and guiding formulation and testing of analytic theoretical descriptions, is demonstrated through studies of the generation and breakup of nanojets, which have led to the derivation of a stochastic hydrodynamic description. Subsequently, I illustrate the use of computations and simulations as tools of discovery, with examples that include the self-organized formation of nanowires, the surprising nanocatalytic activity of small aggregates of gold that, in the bulk form, is notorious for being chemically inert, and the emergence of rotating electron molecules in two-dimensional quantum dots. I conclude with a brief discussion of some key challenges in nanomaterials simulations.
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Affiliation(s)
- Uzi Landman
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332-0430, USA.
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239
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240
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Zheng W, Nilles JM, Thomas OC, Bowen KH. Photoelectron spectroscopy of nickel-benzene cluster anions. J Chem Phys 2005; 122:44306. [PMID: 15740247 DOI: 10.1063/1.1839864] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
(Nickel)(n)(benzene)(m) (-) cluster anions were studied by both mass spectrometry and anion photoelectron spectroscopy. Only Ni(n)(Bz)(m) (-) species for which n > or =m were observed in the mass spectra. No single-nickel Ni(1)(Bz)(m) (-) species were seen. Adiabatic electron affinities, vertical detachment energies, and second transition energies were determined for (n,m)=(2,1), (2,2), (3,1), and (3,2). For the most part, calculations on Ni(n)(Bz)(m) (-) species by B. K. Rao and P. Jena [J. Chem. Phys. 117, 5234 (2002)] were found to be consistent with our results. The synergy between their calculations and our experiment provided enhanced confidence in the theoretically implied magnetic moments of several nickel-benzene complexes. The magnetic moments of small nickel clusters were seen to be extremely sensitive to immediate molecular environmental effects.
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Affiliation(s)
- Weijun Zheng
- Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA
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241
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Pan MH, Liu H, Wang JZ, Jia JF, Xue QK, Li JL, Qin S, Mirsaidov UM, Wang XR, Markert JT, Zhang Z, Shih CK. Quantum growth of magnetic nanoplatelets of Co on Si with high blocking temperature. NANO LETTERS 2005; 5:87-90. [PMID: 15792418 DOI: 10.1021/nl048295s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Self-organized Co nanoplatelets with a singular height, quantized lateral sizes, and unique shape and orientation have been fabricated on a template consisting of ordered Al nanocluster arrays on Si(111)-7 x 7 surfaces. Despite their small volume (a few nm(3)), these nanomagnets exhibit an unusually high blocking temperature (>100 K). The perpendicular direction for easy magnetization, the high blocking temperature, the size tunability, and the epitaxial growth on Si substrates make these nanomagnets important for applications in information technology.
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Affiliation(s)
- Ming-Hu Pan
- State Key Laboratory for Surface Physics and International Center for Quantum Structures, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
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242
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Clavel G, Guari Y, Larionova J, Guérin C. Formation of cyano-bridged molecule-based magnetic nanoparticles within hybrid mesoporous silica. NEW J CHEM 2005. [DOI: 10.1039/b412315h] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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243
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Zhao F, Sun HL, Gao S, Su G. Magnetic properties of EuS nanoparticles synthesized by thermal decomposition of molecular precursors. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b507584j] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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244
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Margeat O, Dumestre F, Amiens C, Chaudret B, Lecante P, Respaud M. Synthesis of iron nanoparticles: Size effects, shape control and organisation. PROG SOLID STATE CH 2005. [DOI: 10.1016/j.progsolidstchem.2005.11.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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245
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Neyman KM, Vayssilov GN, Rösch N. Transition metal clusters and supported species with metal–carbon bonds from first-principles quantum chemistry. J Organomet Chem 2004. [DOI: 10.1016/j.jorganchem.2004.06.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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246
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Moro R, Yin S, Xu X, de Heer WA. Spin uncoupling in free Nb clusters: support for nascent superconductivity. PHYSICAL REVIEW LETTERS 2004; 93:086803. [PMID: 15447214 DOI: 10.1103/physrevlett.93.086803] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Indexed: 05/24/2023]
Abstract
Molecular beam Stern-Gerlach deflection measurements on Nb clusters (Nb(N), N<100) show that at very low temperatures the odd-N clusters deflect due to a single unpaired spin that is uncoupled from the cluster. At higher temperatures the spin is coupled and no deflections are observed. Spin uncoupling occurs concurrently with the transition to the recently found ferroelectric state, which has superconductor characteristics [Science 300, 1265 (2003)]]. Spin uncoupling (also seen in V, Ta, and Al clusters) is analogous to the reduction of spin-relaxation rates observed in bulk superconductors below T(c).
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Affiliation(s)
- Ramiro Moro
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA
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247
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Claydon JS, Xu YB, Tselepi M, Bland JAC, van der Laan G. Direct observation of a bulklike spin moment at the Fe/GaAs(100)-4x6 interface. PHYSICAL REVIEW LETTERS 2004; 93:037206. [PMID: 15323864 DOI: 10.1103/physrevlett.93.037206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Indexed: 05/24/2023]
Abstract
We have used x-ray magnetic circular dichroism, which offers a unique capability to give element specific information at submonolayer sensitivity, to determine the spin and orbital magnetic moments at the Fe/GaAs(100) interface. The wedge samples, grown by molecular beam epitaxy at room temperature, consisted of 0.25-1 monolayer (ML) Fe on GaAs(100)-4x6 capped with 9 ML Co and have shown Fe spin moments of (1.84-1.96)micro(B) and a large orbital enhancement. Our results demonstrate unambiguously that the Fe/GaAs(100)-4x6 interface is ferromagnetic with a bulklike spin moment, which is highly promising for spintronics applications.
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Affiliation(s)
- J S Claydon
- Spintronics Laboratory, Department of Electronics, The University of York, York YO10 5DD, United Kingdom
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248
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Fauth K, Gold S, Heßler M, Schneider N, Schütz G. Cluster surface interactions: small Fe clusters driven nonmagnetic on graphite. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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249
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Wang SG, Li YW, Jiao H, Lu JX, He MY. Adsorptions of Ni8 Cluster on the Regular and Defect Sites of the MgO(001) Surface. J Phys Chem B 2004. [DOI: 10.1021/jp037738y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sheng-Guang Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, P. R. China, Department of Chemistry, East China Normal University, Shanghai, 200062, P. R. China, and Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V., Buchbinderstrasse 5-6, 18055 Rostock, Germany
| | - Yong-Wang Li
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, P. R. China, Department of Chemistry, East China Normal University, Shanghai, 200062, P. R. China, and Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V., Buchbinderstrasse 5-6, 18055 Rostock, Germany
| | - Haijun Jiao
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, P. R. China, Department of Chemistry, East China Normal University, Shanghai, 200062, P. R. China, and Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V., Buchbinderstrasse 5-6, 18055 Rostock, Germany
| | - Jia-Xing Lu
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, P. R. China, Department of Chemistry, East China Normal University, Shanghai, 200062, P. R. China, and Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V., Buchbinderstrasse 5-6, 18055 Rostock, Germany
| | - Ming-Yuan He
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, P. R. China, Department of Chemistry, East China Normal University, Shanghai, 200062, P. R. China, and Leibniz-Institut für Organische Katalyse an der Universität Rostock e.V., Buchbinderstrasse 5-6, 18055 Rostock, Germany
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250
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Matsura V, Guari Y, Larionova J, Guérin C, Caneschi A, Sangregorio C, Lancelle-Beltran E, Mehdi A, Corriu RJP. Synthesis of magnetic silica-based nanocomposites containing Fe3O4nanoparticles. ACTA ACUST UNITED AC 2004. [DOI: 10.1039/b409449b] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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