Many ferroelastic crystals display at sufficiently low measurement frequencies a huge elastic softening below Tc which is caused by domain wall motion. Materials range from perovskites to iron based superconductors and shape memory materials. We present a model - based on Landau-Ginzburg theory including long range elastic interaction between needle shaped ferroelastic domains - to describe the observed superelastic softening. The theory predicts that the domain wall contribution to the elastic susceptibility is different for improper and proper ferroelastic materials. A test of the theory against experimental data on SrTiO3, KMnF3, LaAlO3, La1-xNdxP5O14 and NH4HC2O4.1/2H2O yields excellent agreement.
@article{arxiv.1601.03590,
title = {Giant domain wall response of highly twinned ferroelastic materials},
author = {W. Schranz and H. Kabelka and A. Sarras and M. Burock},
journal= {arXiv preprint arXiv:1601.03590},
year = {2016}
}