High-Resolution Capacitance Dilatometry of Microscopically Thin Samples Using a Miniature Dilatometer

TL;DR

This paper introduces a high-resolution capacitance dilatometer tailored for ultrathin quantum materials, enabling precise thermal expansion and magnetostriction measurements on samples below 500 μm thick, which were previously challenging to analyze.

Contribution

The authors develop a modified mounting configuration for capacitance dilatometry, allowing measurements on microscopically thin samples, expanding the technique's applicability to quantum materials with exotic properties.

Findings

Validated measurements on samples as thin as 40 μm

Reliable performance confirmed with silver, EuB6, and AgCrS2 crystals

Enables studies of emergent phenomena in reduced-dimensional systems

Abstract

We present a novel application of our high-resolution capacitance dilatometer, specifically engineered for the precise characterization of quantum materials. These materials, which often appear as ultrathin, platelet-shaped crystals, are known for exotic phenomena such as superconductivity, topological order and quantum spin liquid. However, these crystals seldom reach macroscopic dimensions, making them unsuitable for conventional dilatometry techniques. By introducing a modified sample-mounting configuration, our design enables high-resolution measurements of thermal expansion and magnetostriction along in-plane crystallographic directions in samples with thicknesses well below 500 $\mu$m. Validation measurements using a Quantum Design PPMS system confirm reliable performance for a 300 $\mu$m-thick silver platelet, relatively hard ferromagnetic EuB$_6$ single crystals down to 50 $\mu$m, and a 40 $\mu$m-thin, soft AgCrS$_2$ single crystal. This advancement significantly broadens the applicability of capacitance dilatometry, providing a powerful platform for investigating emergent phenomena in reduced-dimensional quantum systems.