Magnetostriction and magneto-structural domains in antiferromagnetic YBa$_{2}$Cu$_{3}$O$_{6}$

TL;DR

This study investigates magnetostriction and magneto-structural domains in antiferromagnetic YBa₂Cu₃O₆ using neutron diffraction and dilatometry, revealing domain formation and subtle lattice distortions affecting transport properties.

Contribution

It provides the first detailed measurements of magnetostriction and domain structures in undoped YBa₂Cu₃O₆, highlighting their impact on material properties.

Findings

Magneto-structural domains of ~240 nm form below T_N

Minute orthorhombic distortion observed under magnetic fields

Magnetostriction influences thermal and charge transport

Abstract

We have used high-resolution neutron Larmor diffraction and capacitative dilatometry to investigate spontaneous and forced magnetostriction in undoped, antiferromagnetic YBa$_2$Cu$_3$O$_{6.0}$, the parent compound of a prominent family of high-temperature superconductors. Upon cooling below the N\'eel temperature, $T_N = 420$~K, Larmor diffraction reveals the formation of magneto-structural domains of characteristic size $\sim 240$~nm. In the antiferromagnetic state, dilatometry reveals a minute ($4 \times 10^{-6}$) orthorhombic distortion of the crystal lattice in external magnetic fields. We attribute these observations to exchange striction and spin-orbit coupling induced magnetostriction, respectively, and show that they have an important influence on the thermal and charge transport properties of undoped and lightly doped cuprates.