Large magneto-thermal effect and the spin-phonon coupling in a parent insulating cuprate Pr_{1.3}La_{0.7}CuO_4

TL;DR

This study reveals a significant magneto-thermal effect in Pr_{1.3}La_{0.7}CuO_4, showing strong spin-phonon coupling and highlighting the importance of magnetic field effects on phonon heat transport in cuprates.

Contribution

It demonstrates the large magneto-thermal effect and spin-phonon coupling in an insulating cuprate, emphasizing the role of magnetic field in phonon heat transport analysis.

Findings

Pronounced minimum in thermal conductivity under in-plane magnetic field.

Phonons are scattered by free spins evidenced by specific heat and susceptibility.

Magnetic field dependence of phonon heat transport is significant in cuprates.

Abstract

The magnetic-field (H) dependence of the thermal conductivity \kappa of Pr_{1.3}La_{0.7}CuO_4 is found to show a pronounced minimum for in-plane fields at low temperature, which is best attributed to the scattering of phonons by free spins that are seen by a Schottky-type specific heat and a Curie-Weiss susceptibility. Besides pointing to a strong spin-phonon coupling in cuprates, the present result demonstrates that the H-dependence of the phonon heat transport should not be naively neglected when discussing the \kappa(H) behavior of cuprates, since the Schottky anomaly is ubiquitously found in cuprates at any doping.