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Hand AT, Watson-Sanders BD, Xue ZL. Spectroscopic techniques to probe magnetic anisotropy and spin-phonon coupling in metal complexes. Dalton Trans 2024; 53:4390-4405. [PMID: 38380640 DOI: 10.1039/d3dt03609j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Magnetism of molecular quantum materials such as single-molecule magnets (SMMs) has been actively studied for potential applications in the new generation of high-density data storage using SMMs and quantum information science. Magnetic anisotropy and spin-phonon coupling are two key properties of d- and f-metal complexes. Here, phonons refer to both intermolecular and intramolecular vibrations. Direct determination of magnetic anisotropy and experimental studies of spin-phonon coupling are critical to the understanding of molecular magnetism. This article discusses our recent approach in using three complementary techniques, far-IR and Raman magneto-spectroscopies (FIRMS and RaMS, respectively) and inelastic neutron scatterings (INS), to determine magnetic excited states. Spin-phonon couplings are observed in FIRMS and RaMS. DFT phonon calculations give energies and symmetries of phonons as well as calculated INS spectra which help identify magnetic peaks in experimental INS spectra.
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Affiliation(s)
- Adam T Hand
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.
| | | | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.
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2
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Gálico DA, Murugesu M. Toward Magneto-Optical Cryogenic Thermometers with High Sensitivity: A Magnetic Circular Dichroism Based Thermometric Approach. Angew Chem Int Ed Engl 2023; 62:e202309152. [PMID: 37595074 DOI: 10.1002/anie.202309152] [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: 06/29/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/20/2023]
Abstract
Remote temperature probing at the cryogenic range is of utmost importance for the advancement of future quantum technologies. Despite the notable achievements in luminescent thermometers, accurately measuring temperatures below 10 K remains a challenging endeavor. In this study, we propose a novel magneto-optical thermometric approach based on the magnetic-circular dichroism (MCD) technique, which offers unprecedented capabilities for meticulous temperature variation analysis at cryogenic temperatures. The inherent temperature sensitivity of the MCD C-term, in conjunction with both positive and negative signals, enables highly sensitive magneto-optical temperature probing. Additionally, a groundbreaking relative thermal sensitivity value of 95.3 % K-1 at 2.54 K can be achieved using a mononuclear lanthanide complex, [[Ho(acac)3 (phen)], in the presence of a 0.25 T applied magnetic field and using a combination of multiparametric thermal read-out with multiple regression. These results unequivocally demonstrate the viability and effectiveness of our methodology for cryogenic temperature sensing.
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Affiliation(s)
- Diogo Alves Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie, Ottawa, Ontario, K1N 6N5, Canada
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3
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Errulat D, Harriman KLM, Gálico DA, Ovens JS, Mansikkamäki A, Murugesu M. Aufbau vs. non-Aufbau ground states in two-coordinate d7 single-molecule magnets. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00912e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Magnetic anisotropy is generated in two related d7 single-molecule magnets; (1) via 3d-4s orbital mixing in FeI; and (2) a non-Aufbau ground state in CoII, demonstrating that the electronic configurations are large retained independent of geometry.
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Affiliation(s)
- Dylan Errulat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Katie L. M. Harriman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Diogo A. Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jeffrey S. Ovens
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Akseli Mansikkamäki
- A. Mansikkamäki, NMR Research Unit, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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4
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Lenz S, Bamberger H, Hallmen PP, Thiebes Y, Otto S, Heinze K, van Slageren J. Chromium(iii)-based potential molecular quantum bits with long coherence times. Phys Chem Chem Phys 2019; 21:6976-6983. [PMID: 30869710 DOI: 10.1039/c9cp00745h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular quantum bits based on copper(ii) or vanadium(iv) have been shown to possess long coherence times on multiple occasions. In contrast, studies in which non-spin-½ ions are employed are relatively scarce. High-spin ions provide additional states that can be used to encode further quantum bits. Furthermore, an optical rather than a microwave readout of molecular quantum bits is highly desirable, because in principle it could allow addressing at the single quantum bit level. The chromium(iii) complex [Cr(ddpd)2]3+ (ddpd = N,N'-dimethyl-N,N'-dipyridine-2-yl-pyridine-2,6-diamine) combines both the large spin (S = 3/2) and optical activity (strong, long lived luminescence). Here we demonstrate that the compound possesses coherence times of up to 8.4(1) μs, which are much longer (at least three times) than those for other chromium(iii)-based compounds. On the other hand, it is proved to be impossible to read out or influence the quantum state by optical means, underlining that further work is needed in this direction.
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Affiliation(s)
- Samuel Lenz
- Institute of Physical Chemistry and Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
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5
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Reta D, Moreira IDPR, Illas F. Calix[n]arene-based polyradicals: enhancing ferromagnetism by avoiding edge effects. Phys Chem Chem Phys 2017; 19:24264-24270. [DOI: 10.1039/c7cp04145d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The absence of edges in circular structures derived from 1,3-arylmethyl polyradical results in realistic molecules showing largely stabilized high-spin ground states.
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Affiliation(s)
- Daniel Reta
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
- School of Chemistry
| | - Ibério de P. R. Moreira
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB)
- Universitat de Barcelona
- 08028 Barcelona
- Spain
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6
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Rozbořil J, Rechkemmer Y, Bloos D, Münz F, Wang CN, Neugebauer P, Čechal J, Novák J, van Slageren J. Magneto-optical investigations of molecular nanomagnet monolayers. Dalton Trans 2016; 45:7555-8. [PMID: 27080152 DOI: 10.1039/c6dt00839a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report field-dependent magnetization measurements on monolayers of [Dy(Pc)2] on quartz, prepared by the Langmuir-Blodgett technique. The films are thoroughly characterized by means of X-ray reflectivity and atomic force microscopy. The magnetisation of the sample is measured through the magnetic circular dichroism of a ligand-based electronic transition.
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Affiliation(s)
- J Rozbořil
- CEITEC MU, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic and Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic.
| | - Y Rechkemmer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - D Bloos
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - F Münz
- CEITEC MU, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic and Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic.
| | - C N Wang
- CEITEC MU, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic and Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic.
| | - P Neugebauer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
| | - J Čechal
- CEITEC BUT, Brno University of Technology, Purkyňova 123, 61200 Brno, Czech Republic and Institute of Physical Engineering, Brno University of Technology, Technická 2896/2, 61669, Brno, Czech Republic
| | - J Novák
- CEITEC MU, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic and Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 61137 Brno, Czech Republic.
| | - J van Slageren
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
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Rechkemmer Y, Breitgoff FD, van der Meer M, Atanasov M, Hakl M, Orlita M, Neugebauer P, Neese F, Sarkar B, van Slageren J. A four-coordinate cobalt(II) single-ion magnet with coercivity and a very high energy barrier. Nat Commun 2016; 7:10467. [PMID: 26883902 PMCID: PMC4757785 DOI: 10.1038/ncomms10467] [Citation(s) in RCA: 309] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/11/2015] [Indexed: 12/23/2022] Open
Abstract
Single-molecule magnets display magnetic bistability of molecular origin, which may one day be exploited in magnetic data storage devices. Recently it was realised that increasing the magnetic moment of polynuclear molecules does not automatically lead to a substantial increase in magnetic bistability. Attention has thus increasingly focussed on ions with large magnetic anisotropies, especially lanthanides. In spite of large effective energy barriers towards relaxation of the magnetic moment, this has so far not led to a big increase in magnetic bistability. Here we present a comprehensive study of a mononuclear, tetrahedrally coordinated cobalt(II) single-molecule magnet, which has a very high effective energy barrier and displays pronounced magnetic bistability. The combined experimental-theoretical approach enables an in-depth understanding of the origin of these favourable properties, which are shown to arise from a strong ligand field in combination with axial distortion. Our findings allow formulation of clear design principles for improved materials. Bistable single-molecule magnets potentially allow information storage at extremely high densities. Here, the authors study an air- and moisture-stable mononuclear tetrahedral cobalt(II) complex, elucidating the origin of its pronounced magnetic bistability.
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Affiliation(s)
- Yvonne Rechkemmer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart D-70569, Germany
| | - Frauke D Breitgoff
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart D-70569, Germany
| | - Margarethe van der Meer
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin D-14195, Germany
| | - Mihail Atanasov
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, Mülheim an der Ruhr D-45470, Germany.,Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria
| | - Michael Hakl
- Laboratoire national des champs magnétiques intenses, CNRS-UJF-UPS-INS, Grenoble F-38042, France
| | - Milan Orlita
- Laboratoire national des champs magnétiques intenses, CNRS-UJF-UPS-INS, Grenoble F-38042, France.,Institute of Physics, Charles University in Prague, Prague CZ-12116, Czech Republic
| | - Petr Neugebauer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart D-70569, Germany
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, Mülheim an der Ruhr D-45470, Germany
| | - Biprajit Sarkar
- Institut für Chemie und Biochemie, Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34-36, Berlin D-14195, Germany
| | - Joris van Slageren
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, Stuttgart D-70569, Germany
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8
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Liu J, Krzystek J, Hill S, Barrios L, Aromı́ G. Elucidating Magnetic Exchange and Anisotropy in Weakly Coupled MnIII Dimers. Inorg Chem 2012; 52:718-23. [DOI: 10.1021/ic301849f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Junjie Liu
- Department of Physics, University of Florida, Gainesville, Florida 32301, United States
| | | | | | - Leonı́ Barrios
- Departament de Química Inorgànica, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Guillem Aromı́
- Departament de Química Inorgànica, Universitat de Barcelona, 08028 Barcelona, Spain
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9
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Piga F, Moro F, Krivokapic I, Blake AJ, Edge R, McInnes EJL, Evans DJ, McMaster J, Slageren JV. Magnetic properties of a novel family of ferrous cubanes. Chem Commun (Camb) 2012; 48:2430-2. [DOI: 10.1039/c2cc16853g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Domingo N, Bellido E, Ruiz-Molina D. Advances on structuring, integration and magnetic characterization of molecular nanomagnets on surfaces and devices. Chem Soc Rev 2012; 41:258-302. [DOI: 10.1039/c1cs15096k] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Frequency domain magnetic resonance and magnetic circular dichroism studies on Ni4 cubane molecular nanomagnets: A magnetic anisotropy investigation. Inorganica Chim Acta 2010. [DOI: 10.1016/j.ica.2010.08.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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