Switching the anisotropy barrier of a single-ion magnet by symmetry change from quasi-D_(5h) to quasi-O_h

摘要

A reversible single-crystal-to-single-crystal transformation is used to dramatically change the relaxation behavior of a single-ion magnet. The coordination geometry of the Dy~(III) site of a [Zn-Dy-Zn] complex changes from pentagonal-bipyramid (quasi-D_(5h)) to octahedron (quasi-O_h), inducing an energy barrier change from 305 cm~(-1) (439 K) to a negligible value, respectively. Ab initio calculations reveal that the ideal D_(5h)-Dy~(III) is of perfect axiality with a substantial energy barrier in accordance with the experimental result.