Magnetoelastic relaxations in EuTiO₃

¹ Department of Earth Sciences, University of Cambridge - Downing Street, Cambridge CB2 3EQ, UK
² Cavendish Laboratory, University of Cambridge - Madingley Road, Cambridge CB3 0HE, UK
³ Academic Centre for Materials and Nanotechnology and Faculty of Physics and Applied Computer Science, AGH University of Science and Technology - al. Mickiewicza 30, 30-059 Krakow, Poland
⁴ Division of Physics and Applied Physics, Nanyang Technological University - 637371 Singapore, Singapore
⁵ Department of Physics, University of Crete and FORTH - GR-71003 Heraklion, Greece
⁶ Department of Physics, Waseda University - Tokyo 169-8555, Japan

Received: 5 January 2015
Accepted: 21 February 2015

Abstract

The multiferroic properties of EuTiO₃ are greatly enhanced when a sample is strained, signifying that coupling between strain and structural, magnetic or ferroelectric order parameters is extremely important. Here resonant ultrasound spectroscopy has been used to investigate strain coupling effects, as well as possible additional phase transitions, through their influence on elastic and anelastic relaxations that occur as a function of temperature between 2 and 300 K and with applied magnetic field up to 14 T. Antiferromagnetic ordering is accompanied by acoustic loss and softening, and a weak magnetoelastic effect is also associated with the change in magnetization direction below . Changes in loss due to the influence of magnetic field suggest the existence of magnetic defects which couple with strain and may play a role in pinning of ferroelastic twin walls.