A cascade of magnetic field induced spin transitions in LaCoO3

TL;DR

This study uncovers multiple magnetic phase transitions in LaCoO3 under high magnetic fields, revealing collective spin behavior and complex magnetic textures not explained by simple models.

Contribution

It introduces a model predicting a cascade of four magnetic transitions and spin textures, supported by experimental magnetization and magnetostriction data.

Findings

Two distinct first-order spin transitions observed.

Magnetization plateaux indicate collective spin behavior.

Model predicts four magnetic phase transitions.

Abstract

We present magnetization and magnetostriction studies of the insulating perovskite LaCoO3 in magnetic fields approaching 100 T. In marked contrast with expectations from single-ion models, the data reveal two distinct first-order spin transitions and well-defined magnetization plateaux. The magnetization at the higher plateau is only about half the saturation value expected for spin-1 Co3+ ions. These findings strongly suggest collective behavior induced by strong interactions between different electronic -- and therefore spin -- configurations of Co3+ ions. We propose a model of these interactions that predicts crystalline spin textures and a cascade of four magnetic phase transitions at high fields, of which the first two account for the experimental data.