| Institution: | 1. School of Chemistry, University College Dublin, Belfield, Dublin, 4 Ireland;2. Univ Rennes, CNRS, IPR (Institut de Physique de Rennes)—UMR 6251, 35000 Rennes, France;3. Department of Physics, Auburn University, Auburn, AL, 36849 USA;4. National High Magnetic Field Laboratory, Los Alamos National Laboratory, Los Alamos, NM, 87545 USA;5. Centre for Nanostructured Media, School of Mathematics and Physics, Queen's University of Belfast, Belfast, BT7 1NN, Northern Ireland UK;6. Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ UK |
| 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 Mn3+ compound Mn(3,5-diBr-sal2(323))]BPh4, 1. The first at 250 K, involves the space group change Cc→Pc and is thermodynamically continuous, while the second, Pc→P1 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-P1 transition |
