Estudo de transições de fase estruturais em fósforo negro

Abstract

The search for new materials, with the possibility of obtaining two-dimensional systems, has increased in recent years. In this perspective, studies on black phosphorus have increased in recent decades and gained space to contribute to the development of highperformance nanodevices. With some investigations in the first century, after its discovery in 1914, black phosphorus, a crystalline material with an orthorhombic structure, aroused interest after mechanical exfoliation, as well as graphene. Some studies have shown that extreme pressures represent a way to gain access to new phases of the crystalline structure, with which interesting physical properties are observed. In this perspective, we present the theoretical study of structural phase transitions in black phosphorus bulk caused by hydrostatic pressures. We analyzed the structural and electronic properties of black phosphorus in the orthorhombic, rhombohedral and cubic phases. We also present, in collaboration with Professor Dr. Luiz Craco, a study with analysis of the electronic structures and electrical resistivity properties of black phosphorus (orthorhombic phase) and gray phosphorus (rhombohedral phase) under pressure, showing Kondo electronic reconstruction with band selection, in the p layer of this phosphorus allotrope . Based on density functional dynamic mean field theory calculations, we show that gray phosphorus can host a three-dimensional Kondo semimetal to a liquid Fermi phase crossover under anisotropic compression, increasing the orbital degeneracy in the layer. In it, the 3p orbital is almost unchanged in both the semiconductor and semimetallic Kondo phases. However, for the liquid Fermi regime, it is predicted that there is strong electronic reconstruction in the orbital nematic phase of gray phosphorus under pressure. These results contribute to the microscopic understanding of the role played by dynamic multi-orbital electronic interactions in the low-energy spectrum of correlated semiconductors and topological semimetals.