Fine-tuning the Local Symmetry to Attain Record Blocking Temperature and Magnetic Remanence in a Single-Ion Magnet

Authors

  • Dr. Liviu Ungur,

    1. Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijenlaan 200F, 3001 Leuven (Belgium)
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  • Jennifer J. Le Roy,

    1. Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5 (Canada)
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  • Dr. Ilia Korobkov,

    1. Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5 (Canada)
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  • Prof. Muralee Murugesu,

    Corresponding author
    1. Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5 (Canada)
    • Muralee Murugesu, Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5 (Canada)

      Liviu F. Chibotaru, Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijenlaan 200F, 3001 Leuven (Belgium)

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  • Prof. Liviu F. Chibotaru

    Corresponding author
    1. Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijenlaan 200F, 3001 Leuven (Belgium)
    • Muralee Murugesu, Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, ON, K1N 6N5 (Canada)

      Liviu F. Chibotaru, Theory of Nanomaterials Group and INPAC-Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijenlaan 200F, 3001 Leuven (Belgium)

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  • L.U. is a post-doc of the Flemish Science Foundation (FWO-Vlaanderen) and also acknowledges the support from the INPAC and Methusalem programs of the KU Leuven. M.M. thanks the University of Ottawa, NSERC, CFI, ORF, and ERA.

Abstract

Remanence and coercivity are the basic characteristics of permanent magnets. They are also tightly correlated with the existence of long relaxation times of magnetization in a number of molecular complexes, called accordingly single-molecule magnets (SMMs). Up to now, hysteresis loops with large coercive fields have only been observed in polynuclear metal complexes and metal-radical SMMs. On the contrary, mononuclear complexes, called single-ion magnets (SIM), have shown hysteresis loops of butterfly/phonon bottleneck type, with negligible coercivity, and therefore with much shorter relaxation times of magnetization. A mononuclear ErIII complex is presented with hysteresis loops having large coercive fields, achieving 7000 Oe at T=1.8 K and field variation as slow as 1 h for the entire cycle. The coercivity persists up to about 5 K, while the hysteresis loops persist to 12 K. Our finding shows that SIMs can be as efficient as polynuclear SMMs, thus opening new perspectives for their applications.

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