Structure and magnetism in $\rm LaCoO_3$

TL;DR

This study investigates the temperature-dependent structural and magnetic properties of LaCoO3, revealing a power-law lattice parameter change near 35K and discussing its implications for magnetic behavior and theoretical calculations.

Contribution

It provides detailed x-ray scattering measurements of LaCoO3's lattice parameter near the transition temperature and analyzes the data in relation to magnetic properties and theoretical models.

Findings

Lattice parameter c(T) follows a power law above 35K

Below 35K, c(T) remains constant within measurement resolution

Results relate structural changes to magnetic behavior in LaCoO3

Abstract

The temperature dependence of the hexagonal lattice parameter $c$ of single crystal $\rm LaCoO_3$ (LCO) with $H=0$ and $800$Oe, as well as LCO bulk powders with $H=0$, was measured using high-resolution x-ray scattering near the transition temperature $T_o\approx 35$K. The change of $c(T)$ is well characterized by a power law in $T-T_o$ for $T>T_o$ and by a temperature independent constant for $T<T_o$ when convoluted with a Gaussian function of width $8.5$K. This behavior is discussed in the context of the unusual magnetic behavior observed in LCO as well as recent generalized gradient approximation calculations.