Uniaxial pressure dependencies of the phase transitions in GdMnO$_3$

TL;DR

This study investigates how uniaxial pressure affects the phase transitions in GdMnO₃, revealing the pressure dependencies of magnetic and ferroelectric transitions through thermal expansion measurements.

Contribution

It provides detailed uniaxial pressure dependencies of phase transition temperatures in GdMnO₃, linking them to magnetic exchange interactions.

Findings

Uniaxial pressure influences magnetic transition temperatures.

Thermal expansion reveals anisotropic pressure effects.

Correlations between pressure and magnetic exchange couplings are discussed.

Abstract

GdMnO$_3$ shows an incommensurate antiferromagnetic order below $\simeq 42$ K, transforms into a canted A-type antiferromagnet below $\simeq 20$ K, and for finite magnetic fields along the b axis ferroelectric order occurs below $\simeq 12$ K. From high-resolution thermal expansion measurements along all three principal axes, we determine the uniaxial pressure dependencies of the various transition temperatures and discuss their correlation to changes of the magnetic exchange couplings in $R$MnO$_3$ ($R = {\rm La, ... Dy}$).