The prediction of a new high-pressure phase of hafnia using first-principles computations

2nd International Conference on Advanced Materials

Al-Khatatbeh, Y.^1 ; Tarawneh, K.^1 ; Hamad, B.^2,3

Department of Basic Sciences, Princess Sumaya University for Technology, Amman

11941, Jordan^1

Physics Department, University of Jordan, Amman

11942, Jordan^2

Physics Department, University of Arkansas, Fayetteville

AR

72701, United States^3

关键词: Birch-Murnaghan equation of state;    First principles;    Hexagonal phase;    Scaling model;    Space Groups;    Stable phase;    Type structures;    Ultrahigh pressure;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/305/1/012006/pdf
DOI  :  10.1088/1757-899X/305/1/012006

来源: IOP

【 摘 要 】

Using density functional theory (DFT) calculations, we predicted a new high-pressure phase of hafnia (HfO2). We found the hexagonal phase (Ni2In-Type structure; space group: P63/mmc) to be the stable phase at ultrahigh pressures greater than ∼386 GPa. Our findings are consistent with recent calculations performed on the similar dioxide ZrO2[M. Durandurdu, J. Solid State Chem. 230, 233 (2015)] where this phase has been claimed to be the most stable at pressures greater than 380 GPa. The Birch-Murnaghan equation of state (BM-EOS) of the new phase shows that this phase is more compressible and less dense than Fe2P-Type phase. Additionally, the hardness calculations using a scaling model confirmed that our newly predicted phase has a similar hardness compared to the other HfO2phases, indicating that none of the HfO2phases can be considered to be superhard.