Electronic and magnetic properties of black phosphorus

TL;DR

This study investigates the electronic and magnetic properties of black phosphorus using ESR, NMR, and microwave conductivity, revealing its semiconducting nature, absence of free charge carriers, and potential as a microwave absorbent.

Contribution

It provides new insights into black phosphorus's electronic structure and magnetic behavior using advanced magnetic resonance and conductivity techniques.

Findings

Black phosphorus shows no free charge carriers or paramagnetic defects.

It behaves as a semiconductor with identifiable charge carrier contributions.

Potential application as a microwave absorbent is suggested.

Abstract

Black phosphorus has emerged as the next member in the graphene inspired two-dimensional materials family. Its electronic and magnetic properties are studied herein using electron and nuclear magnetic resonance techniques (ESR and NMR) and microwave conductivity measurement. The latter is a unique technique to study conductivity on air sensitive samples. The ESR study indicates the absence of free charge carriers and no sign of paramagnetic defects are found. $^{31}$P NMR shows the presence of a characteristic Pake doublet structure due to the interaction between $I = 1/2$ nuclei. Microwave conductivity shows, in accordance with the ESR results, that black phosphorus behaves as a semiconductor and we identify extrinsic and intrinsic charge carrier contributions to the conductivity and extracted the sizes of the gaps. ESR measurement also yields that bP might find applications as a microwave absorbent.