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Gálico DA, Rodrigues EM, Halimi I, Toivola J, Zhao H, Xu J, Moilanen JO, Liu X, Hemmer E, Murugesu M. Confining single Er 3+ ions in sub-3 nm NaYF 4 nanoparticles to induce slow relaxation of the magnetisation. Nat Commun 2024; 15:3498. [PMID: 38664382 PMCID: PMC11045814 DOI: 10.1038/s41467-024-47682-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Molecular systems known as single-molecule magnets (SMMs) exhibit magnet-like behaviour of slow relaxation of the magnetisation and magnetic hysteresis and have potential application in high-density memory storage or quantum computing. Often, their intrinsic magnetic properties are plagued by low-energy molecular vibrations that lead to phonon-induced relaxation processes, however, there is no straightforward synthetic approach for molecular systems that would lead to a small amount of low-energy vibrations and low phonon density of states at the spin-resonance energies. In this work, we apply knowledge accumulated over the last decade in molecular magnetism to nanoparticles, incorporating Er3+ ions in an ultrasmall sub-3 nm diamagnetic NaYF4 nanoparticle (NP) and probing the slow relaxation dynamics intrinsic to the Er3+ ion. Furthermore, by increasing the doping concentration, we also investigate the role of intraparticle interactions within the NP. The knowledge gained from this study is anticipated to enable better design of magnetically high-performance molecular and bulk magnets for a wide variety of applications, such as molecular electronics.
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Affiliation(s)
- Diogo A Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Emille M Rodrigues
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Ilias Halimi
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada
| | - Juho Toivola
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland
| | - He Zhao
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Jiahui Xu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Jani O Moilanen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland.
| | - Xiaogang Liu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore
| | - Eva Hemmer
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
- Centre for Advanced Materials Research (CAMaR), University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
- Centre for Advanced Materials Research (CAMaR), University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
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Slow-Relaxation Behavior of a Mononuclear Co(II) Complex Featuring Long Axial Co-O Bond. NANOMATERIALS 2022; 12:nano12040707. [PMID: 35215035 PMCID: PMC8875892 DOI: 10.3390/nano12040707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/13/2022] [Accepted: 02/18/2022] [Indexed: 02/01/2023]
Abstract
Co(II) mononuclear complex with different coordination geometry would display various of field-induced single-ion magnet (SIM) behaviors. Here, we identify a field-induced single-ion magnet in a mononuclear complex Co(H2DPA)2·H2O (H2DPA = 2,6-pyridine-dicarboxylic acid) by the hydrothermal method. The long axial Co-O coordination bond (Co1‧‧‧O3) can be formed by Co1 and O3. Therefore, Co(II) ion is six-coordinated in a distorted elongated octahedron. AC magnetization susceptibilities show that the effective energy barrier is up to 43.28 K. This is much larger than most mononuclear Co(II). The distorted elongated octahedron caused by the axial Co-O coordination bond is responsible for the high effective energy barrier. The distribution of electron density in Co1 and O3 atoms in the long axial bond would influence the magnetic relaxation process in turn. Our work deepens the relationship between the effective energy barrier and the weak change of ligand field by long axial bonds, which would facilitate constructing SIM with high energy temperature.
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Cobalt(II) Complexes Based on Benzylmalonate Anions Exhibiting Field-Induced Single-Ion Magnet Slow Relaxation Behavior. CRYSTALS 2020. [DOI: 10.3390/cryst10121130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The reaction of (NBu4)2Bzmal (where Bzmal2− is benzylmalonate dianion) with Co(OAc)2∙4H2O gives the [Co(Bzmal)(EtOH)(H2O)]n 2D-polymer (1). The addition of 2,2′-bipyridine (bpy) to the starting system results in the [Co(Bzmal)(bpy)2]·H2O·EtOH molecular complex (2). Their molecular and crystal structures were analyzed by single-crystal X-ray crystallography. An analysis of the static magnetic data supported by the SA-CASSCF/NEVPT2 calculations revealed the presence of easy-plane magnetic anisotropy in both complexes. The AC susceptibility data confirm that both complexes show a slow field-induced (HDC = 1000 Oe) magnetic relaxation behavior.
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Sanakis Y, Krzystek J, Maganas D, Grigoropoulos A, Ferentinos E, Kostakis MG, Petroulea V, Pissas M, Thirunavukkuarasu K, Wernsdorfer W, Neese F, Kyritsis P. Magnetic Properties and Electronic Structure of the S = 2 Complex [Mn III{(OPPh 2) 2N} 3] Showing Field-Induced Slow Magnetization Relaxation. Inorg Chem 2020; 59:13281-13294. [PMID: 32897702 DOI: 10.1021/acs.inorgchem.0c01636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The high-spin S = 2 Mn(III) complex [Mn{(OPPh2)2N}3] (1Mn) exhibits field-induced slow relaxation of magnetization (Inorg. Chem. 2013, 52, 12869). Magnetic susceptibility and dual-mode X-band electron paramagnetic resonance (EPR) studies revealed a negative value of the zero-field-splitting (zfs) parameter D. In order to explore the magnetic and electronic properties of 1Mn in detail, a combination of experimental and computational studies is presented herein. Alternating-current magnetometry on magnetically diluted samples (1Mn/1Ga) of 1Mn in the diamagnetic gallium analogue, [Ga{(OPPh2)2N}3], indicates that the slow relaxation behavior of 1Mn is due to the intrinsic properties of the individual molecules of 1Mn. Investigation of the single-crystal magnetization of both 1Mn and 1Mn/1Ga by a micro-SQUID device reveals hysteresis loops below 1 K. Closed hysteresis loops at a zero direct-current magnetic field are observed and attributed to fast quantum tunneling of magnetization. High-frequency and -field EPR (HFEPR) spectroscopic studies reveal that, apart from the second-order zfs terms (D and E), fourth-order terms (B4m) are required in order to appropriately describe the magnetic properties of 1Mn. These studies provide accurate spin-Hamiltonian (sH) parameters of 1Mn, i.e., zfs parameters |D| = 3.917(5) cm-1, |E| = 0.018(4) cm-1, B04 = B42 = 0, and B44 = (3.6 ± 1.7) × 10-3 cm-1 and g = [1.994(5), 1.996(4), 1.985(4)], and confirm the negative sign of D. Parallel-mode X-band EPR studies on 1Mn/1Ga and CH2Cl2 solutions of 1Mn probe the electronic-nuclear hyperfine interactions in the solid state and solution. The electronic structure of 1Mn is investigated by quantum-chemical calculations by employing recently developed computational protocols that are grounded on ab initio wave function theory. From computational analysis, the contributions of spin-spin and spin-orbit coupling to the magnitude of D are obtained. The calculations provide also computed values of the fourth-order zfs terms B4m, as well as those of the g and hyperfine interaction tensor components. In all cases, a very good agreement between the computed and experimentally determined sH parameters is observed. The magnetization relaxation properties of 1Mn are rationalized on the basis of the composition of the ground-state wave functions in the absence or presence of an external magnetic field.
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Affiliation(s)
- Yiannis Sanakis
- Institute of Nanoscience and Nanotechnolgy, National Centre of Scientific Research "Demokritos", Aghia Paraskevi 15310, Attiki, Greece
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Dimitrios Maganas
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Alexios Grigoropoulos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Eleftherios Ferentinos
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Marios G Kostakis
- Analytical Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens,15771 Athens, Greece
| | - Vasiliki Petroulea
- Institute of Nanoscience and Nanotechnolgy, National Centre of Scientific Research "Demokritos", Aghia Paraskevi 15310, Attiki, Greece
| | - Michael Pissas
- Institute of Nanoscience and Nanotechnolgy, National Centre of Scientific Research "Demokritos", Aghia Paraskevi 15310, Attiki, Greece
| | | | - Wolfgang Wernsdorfer
- Physikalisches Institut, Karlsruher Institut für Technologie, Wolfgang-Gaede-Strasse 1, 76131 Karlsruhe, Germany.,Institute of Quantum Materials and Technologies, Karlsruher Institut für Technologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Panayotis Kyritsis
- Inorganic Chemistry Laboratory, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
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Wu Y, Xi J, Yang J, Song W, Luo S, Wang Z, Liu X. Coligand effects on the architectures and magnetic properties of octahedral cobalt( ii) complexes with easy-axis magnetic anisotropy. CrystEngComm 2020. [DOI: 10.1039/c9ce01871a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Coligand effects lead to two mononuclear octahedral Co(ii) complexes exhibiting easy-axis magnetic anisotropies and distinct magnetic properties.
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Affiliation(s)
- Yuewei Wu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- National Demonstration Center for Experimental Chemistry Education
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
| | - Jing Xi
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- National Demonstration Center for Experimental Chemistry Education
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
| | - Jinhui Yang
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- National Demonstration Center for Experimental Chemistry Education
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
| | - Weiming Song
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- National Demonstration Center for Experimental Chemistry Education
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
| | - Shuchang Luo
- School of Chemical Engineering
- Guizhou University of Engineering Science
- Bijie
- China
| | - Zheng Wang
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- National Demonstration Center for Experimental Chemistry Education
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
| | - Xiangyu Liu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- National Demonstration Center for Experimental Chemistry Education
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
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