Study of the structural and electronic properties of YC using DFT: The true ground state is a NiAs-like structure

2nd International Meeting for Researchers in Materials and Plasma Technology

物理学;材料科学

Abdel-Rahim, G.P.^1,2 ; Rodríguez, M.J.A.^2 ; Moreno-Armenta, M.G.^3

Grupo PERSEO, Universidad Antonio Nariño Sede Bogotá, Colombia^1

Grupo de Estudio de Materiales - GEMa, Departamento de Física, Universidad Nacional de Colombia, Sede Bogotá, Colombia^2

Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Ensenada, BC, Mexico^3

关键词: Cesium chloride;    Cohesion energy;    Density of state;    Generalized gradient approximations;    Metallic behaviors;    Sodium chloride (NaCl);    Structural and electronic properties;    Transition pressure;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/466/1/012010/pdf
DOI  :  10.1088/1742-6596/466/1/012010

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

We study the structural and electronic properties of YC in volume using density functional theory (DFT) within the generalized gradient approximation (GGA), using the scheme of Wu-Cohen 2006 and Tran et al. 2007. Several crystal structures were considered: Nickel Arsenide (NiAs), Sodium Chloride (NaCl), Cesium Chloride (CsCl), and zincblende (ZB). A new fact that we present in this paper is the inclusion of the NiAs-like structure, which is the true ground state (GS) for YC. We calculated the density of states (DOS) and the band structure and found that YC is non-magnetic and its behavior is metallic-like. The lattice parameter alatt is 3.69 A and the c/a = 1.47. Cohesion energy (Ecoh) is -12.90 eV, which is very close to Ecoh of the NaCl structure. Therefore, YC exists in these two structures. Our results with respect to alatt, bulk modulus (B), Ecoh, and the main features of the electronic properties are in good agreement with those found by other researchers. Other researchers found a transition from NaCl to CsCl, but we found a new transition from NiAs to CsCl, where the volume diminishes ∼10% and its transition pressure (PT ∼79 GPa) is very close to the 80 GPa of the former. The contraction can fracture the material if it is worked on near the transition. For pressures before and after the transition, YC maintains non-magnetic and metallic behaviors.