An Inconspicuous Six-Coordinate Neutral DyIII Single-Ion Magnet with Remarkable Magnetic Anisotropy and Stability

Min Li; Haipeng Wu; Zhengqiang Xia; Liviu Ungur; Dan Liu; Liviu F Chibotaru; Hongshan Ke; Sanping Chen; Shengli Gao

doi:10.1021/acs.inorgchem.0c00616

An Inconspicuous Six-Coordinate Neutral Dy^III Single-Ion Magnet with Remarkable Magnetic Anisotropy and Stability

Inorg Chem. 2020 May 18;59(10):7158-7166. doi: 10.1021/acs.inorgchem.0c00616. Epub 2020 May 3.

Authors

Min Li¹, Haipeng Wu¹, Zhengqiang Xia¹, Liviu Ungur², Dan Liu³, Liviu F Chibotaru⁴, Hongshan Ke¹, Sanping Chen¹, Shengli Gao¹

Affiliations

¹ Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, China.
² Department of Chemistry, National University of Singapore, Block S8 Level 3, 3 Science Drive 3, 117543, Singapore.
³ Institute of Flexible Electronics (IFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, China.
⁴ Theory of Nanomaterials Group and Institute of Nanoscale Physics and Chemistry -INPAC, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium.

PMID: 32363861
DOI: 10.1021/acs.inorgchem.0c00616

Abstract

It is a crucial challenge to address both magnetic anisotropy and stability for single-molecule magnets (SMMs) used in next-generation nanodevices. Highly axial lanthanide SMMs with neutral charge and moderate coordination numbers represent promising magnetic materials. Here, using iodide ions with large volume and low surface charge density as weak donors, we report a six-coordinate neutral dysprosium SMM [Dy(Cy₃PO)₂I₃(CH₃CN)] with a certain degree of stability exhibiting a huge thermal barrier of 1062 K and hysteresis loops open up to 9 K. Through the elaborate reduction of ligand field strength, an apparent strongly axial crystal field is provided which elicits prominent crystal-field splitting and high axiality with the thermally activated relaxation via the third-excited Kramers' doublet. Moreover, the profound influence of strong equatorial ligand substitution on the electronic structure and relaxation pathway is clearly explored in Dy^III analogues. The result suggests the great potential of the reducing the transverse ligand field in the improvement of SMMs performance.