Electronic properties of air-sensitive nanomaterials probed with microwave impedance measurements

TL;DR

This paper demonstrates the use of microwave impedance measurements as a contactless method to characterize the electronic properties of air-sensitive nanomaterials, enabling studies on powders and novel phases.

Contribution

It introduces microwave cavity perturbation as a versatile, contactless technique for probing the conductivity of air-sensitive nanomaterials in powder form.

Findings

Successful characterization of conductivity in doped black phosphorus.

Observation of semiconducting-metallic crossover in carbon nanotubes.

Study of vortex motion in K3C60 superconductor.

Abstract

Characterization of electronic properties of novel materials is of great importance for exploratory materials development and also for the discovery of new correlated phases. As several novel compounds are available in powder form only, contactless methods, which also work on air sensitive samples, are higly desired. We present that the microwave cavity perturbation technique is a versatile tool to study conductivity in such systems. The examples include studies on semiconducting-metallic crossover in carbon nanotubes upon alkali doping, study of vortex motion in the K$_3$C$_{60}$ superconductor, and the characterization of various alkali atom doped phases of black phosphorus.