Magnetic field driven novel phase transitions in EuTiO$_3$

TL;DR

This study investigates how external magnetic fields influence the structural and magnetic phase transitions of EuTiO$_3$, revealing strong spin-lattice interactions and the emergence of magnetic domains at specific temperatures.

Contribution

It provides new insights into magnetic field effects on EuTiO$_3$, highlighting the role of spin-lattice coupling in high-temperature phase behavior and magnetic domain formation.

Findings

Lattice effects at ~200K and 250K become more pronounced under magnetic fields.

Sign change in magnetostriction at ~200K indicates a shift from ferromagnetic to antiferromagnetic behavior.

Magnetic field influences the local magnetic properties and phase transitions in EuTiO$_3$.

Abstract

The influence of an external static magnetic field (up to 480 mT)on the structural properties of EuTiO$_3$ (ETO) polycrystalline samples was examined by powder XRD at the Elettra synchrotron facilities in the temperature range 100-300K. While the cubic to tetragonal structural phase transition temperature in this magnetic field range remains almost unaffected, significant lattice effects appear at two characteristic temperatures (~200K and 250K), which becomes more pronounced at a critical threshold magnetic field. At ~200K a change in the sign of the magnetostriction is detected attributed to a modification of the local magnetic properties from intrinsic ferromagnetism to intrinsic antiferromagnetism. These data are a clear indication that strong spin-lattice interactions govern also the high temperature phase of ETO and trigger the appearance of magnetic domain formation and novel phase transitions