The incredible diversity of structural and magnetic instabilities in EuTiO3: from paramagnetic to spin glass, spin liquid and antiferromagnetic order

TL;DR

This paper investigates the complex structural and magnetic phase transitions in EuTiO3, revealing multiple instabilities and magnetic states through combined experimental and theoretical approaches.

Contribution

It uncovers additional low-temperature instabilities in EuTiO3 using lattice dynamics, spin-phonon interactions, and a Landau free energy model, expanding understanding of its phase behavior.

Findings

Identification of two new instabilities below TS

Agreement of new transition temperatures with experimental data

Evidence of diverse magnetic and structural phases

Abstract

The perovskite oxide EuTiO3 (ETO) has attracted increased scientific interest due to its potential multiferroic properties and magnetic activity above and below its structural phase transition at TS=282K. Various experiments have indirectly evidenced that this transition is neither a cubic tetragonal nor the only one occurring in ETO. Here, we show new results demonstrating two further instabilities below TS based on lattice dynamics and spin-phonon interactions combined with a Landau free energy model with coupled order parameters. The new transition temperatures perfectly agree with available experimental data where further instabilities have been anticipated.