Pressure-induced superconductivity in LaP2 with graphenelike phosphorus layer

TL;DR

This study reports the discovery of pressure-induced superconductivity in LaP2, featuring graphene-like phosphorus layers, with superconductivity emerging around 30 GPa and Tc reaching 7.8 K at 78 GPa, supported by experimental and theoretical evidence.

Contribution

It demonstrates the emergence of superconductivity in LaP2 under high pressure and reveals the presence of graphene-like phosphorus layers through combined experimental and computational methods.

Findings

Superconductivity appears around 30 GPa in LaP2.

Tc increases monotonically with pressure, reaching 7.8 K at 78 GPa.

Structural transition to P6/mmm phase under high pressure is confirmed.

Abstract

Materials with graphene-like layers attract tremendous attention due to their electronic structures and superconducting properties. In this study, we synthesized LaP2 polycrystalline and observed a superconducting transition around 30 GPa. The critical temperature Tc increases monotonically with pressure, which is nearing saturation and reaches 7.8 K at 78 GPa. The synchrotron X-ray diffraction experiments confirm the superconducting transition originates from a structure transition to the P6/mmm phase under high pressure, suggesting the observation of graphene-like phosphorus layers in transition metal phosphides. By first-principles calculations, we provide more evidence for the stability of the graphene-like phosphorus layers in LaP2. Our findings are helpful for the understanding of the LaP2 phase diagram under high pressure, and could shed light on the research of unique structures in transition metal phosphides under high pressure.