Magnetocaloric effect measurements in ultrahigh magnetic fields up to 120 T

TL;DR

This paper demonstrates measurements of the magnetocaloric effect in the spin-ice compound Ho2Ti2O7 under ultrahigh magnetic fields up to 120 T, revealing rapid temperature changes linked to crystal-field level crossings.

Contribution

It introduces a novel measurement technique using RF resistivity with a thin-film thermometer for high-field MCE detection up to 120 T.

Findings

Detection of rapid temperature change at high fields

Observation of giant MCE at low fields

Discussion of measurement delays and future improvements

Abstract

We report proof-of-concept measurements of the magnetocaloric effect (MCE) in ultrahigh magnetic fields up to 120 T for the classical spin-ice compound Ho$_{2}$Ti$_{2}$O$_{7}$. Radio-frequency resistivity measurements using an Au$_{16}$Ge$_{84}$ thin-film thermometer enable us to detect a rapid change in the sample temperature associated with a crystal-field level crossing in the high-field region in addition to a giant MCE at low fields. We discuss a possible delay in the temperature response and outline prospects for more precise MCE measurements in destructive pulsed fields.