Bulk-sensitive Imaging of Twin Domains in La$_{2-x}$Sr$_x$CuO$_4$ under Uniaxial Pressure

TL;DR

This study uses bulk-sensitive x-ray microdiffraction to image twin domains in La$_{2-x}$Sr$_x$CuO$_4$ under uniaxial pressure, revealing asymmetric and complex domain responses to compression and tension.

Contribution

It provides the first detailed imaging of twin domain behavior in La$_{2-x}$Sr$_x$CuO$_4$ under uniaxial pressure, highlighting asymmetric responses and non-linear effects.

Findings

Twin domains with shorter lattice parameters are unstable under compression.

Moderate compressive pressure can eliminate certain twin domains.

Tensile pressure causes only slight changes in domain structure.

Abstract

We report our study of twin domains in $La_{2-x}Sr_x CuO_4$ under uniaxial pressure. Using bulk-sensitive x-ray microdiffraction in Laue geometry, we image the distribution of twin domains at room temperature. When compressive uniaxial pressure is applied along one of the in-plane crystallographic axes, the domain population changes dramatically. We observe that the twin domain with shorter lattice parameter along the direction of pressure is unstable under compression, and disappears completely with only moderate pressure. On the other hand, application of tensile pressure changes the domain structure only slightly, demonstrating the asymmetric response of the sample to uniaxial pressure. Our observations suggest that a crystal's response to uniaxial pressure is complex and could deviate easily from the linear-response regime.