Superconducting LaP2H2 with graphenelike phosphorus layers

TL;DR

This paper predicts a new pressure-stable superconducting compound, LaP2H2, with graphenelike phosphorus layers, exhibiting high transition temperatures at relatively low pressures, expanding the understanding of superconducting materials.

Contribution

The study introduces a novel pressure-induced structure of LaP2H2 with graphenelike phosphorus layers, demonstrating its superconductivity and higher transition temperature compared to similar compounds.

Findings

LaP2H2 is stable under pressure with graphenelike phosphorus layers.

LaP2H2 exhibits superconductivity with a higher transition temperature than LaPH6.

Superconductivity is dominated by the phosphorus layer and La atom coupling.

Abstract

Novel structural building blocks in compounds could induce interesting physical and chemical properties. Although phosphorus tends to form very different motifs, the existence of lone pair electrons has always prevented the formation of graphenelike structures. Here, the application of first-principles swarm structural calculations has allowed us to predict the stability of pressure-induced hexagonal LaP2H2 containing graphenelike phosphorus, which derives from the trigonal bipyramid configuration of P atoms regulated by symmetric hydrogen bonds. LaP2 in LaP2H2 has the same configuration as MgB2, and P and H atoms form a three-dimensional framework as H3S. Interestingly, LaP2H2 shows a superconductivity dominated by the graphenelike phosphorus layer and its coupling with La atoms. On the other hand, LaP2H2 is not only superconducting at a lower pressure than the H-rich LaPH6, but it also shows a superconducting transition temperature three times higher. Our work provides an example which extends the landscape of conventional superconductors at lower pressures.