A capacitive displacement system for studying the piezoelectric strain and its temperature variation

TL;DR

This paper presents a high-precision capacitive displacement system capable of measuring piezoelectric strain and its temperature dependence in bulk and thin film materials, enabling detailed analysis of piezoelectric properties across a wide temperature range.

Contribution

The paper introduces a novel capacitive displacement measurement system with sub-nanometer resolution and temperature variation capabilities for studying piezoelectric strain in various materials.

Findings

Precise measurement of AC displacement down to 2 pm.

Ability to measure large displacements within ±25 μm.

Experimental validation on quartz, PZT ceramics, and BaTiO₃.

Abstract

A capacitive displacement system was constructed to measure the electric-field-induced piezoelectric strain in the simple form of either a bulk or thin film. The system can determine an AC displacement of 2 pm precisely by using a lock-in detection, and can measure the large displacement within a range of $\pm$ 25 $\mu$m with a sub-nanometer resolution. The system can also be used to measure the variation in strain within a temperature range of 210 - 450 K, allowing the evaluation of the temperature coefficient of a piezoelectric constant and the studies on the effects of a phase transition on the piezoelectric response. Experimental results on quartz, PZT ceramics and thin films, and BaTiO$_3$ confirm the capabilities of the developed system.