Stress‐Induced Domain Wall Motion in a Ferroelastic Mn<sup>3+</sup> Spin Crossover Complex
Vibe B. Jakobsen, Elżbieta Trzop, Laurence C. Gavin, Emiel Dobbelaar, Shalinee Chikara, X. X. Ding, Kane Esien, Helge Müller‐Bunz, Solveig Felton, Vivien S. Zapf, Éric Collet, Michael A. Carpenter, Grace G. Morgan
Abstract
Abstract Domain wall motion is detected for the first time during the transition to a ferroelastic and spin state ordered phase of a spin crossover complex. Single‐crystal X‐ray diffraction and resonant ultrasound spectroscopy (RUS) revealed two distinct symmetry‐breaking phase transitions in the mononuclear Mn 3+ compound [Mn(3,5‐diBr‐sal 2 (323))]BPh 4 , 1. The first at 250 K, involves the space group change Cc → Pc and is thermodynamically continuous, while the second, Pc → P 1 at 85 K, is discontinuous and related to spin crossover and spin state ordering. Stress‐induced domain wall mobility was interpreted on the basis of a steep increase in acoustic loss immediately below the the Pc ‐ P 1 transition