Fine-tuning the local symmetry to attain record blocking temperature and magnetic remanence in a single-ion magnet

Journal article

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.

Authors: Ungur, L; le Roy, J; Korobkov, I; Murugesu, M; Chibotaru, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Angewandte Chemie International Edition
• Volume: 53
• Issue: 17
• Pages: 4413–4417
• Publication date: 2014-03-20
• DOI: 10.1002/anie.201310451
• EISSN: 1521-3773
• ISSN: 1433-7851
• Language: English
• Keywords: magnetic remanence; quantum chemistry; single-molecule magnets; lanthanides; magnetic hysteresis