First Principles Phase Diagram Calculations for the Octahedral-Interstitial System $HfO_{X}$, $0 \leq X \leq 1/2$

Benjamin P. Burton; Axel van de Walle

paper

First Principles Phase Diagram Calculations for the Octahedral-Interstitial System $H f O_{X}$ , $0 \leq X \leq 1/2$

arXiv:1107.4318

Abstract

First principles based phase diagram calculations were performed for the hexagonal closest packed octahedral-interstitial solid solution system $α H f O_{X} ($ αHf[ ]_{1-X}O_{X} $; [] = V a c an cy;$ 0 \leq X \leq 1/2 $) . T h ec l u s t er e x p an s i o nm e t h o d w a s u se d t o d o a g r o u n d s t a t e ana l y s i s, an d t oc a l c u l a t e t h e p ha se d ia g r am . T h e p r e d i c t e dd ia g r amha s f o u r or d er e d g r o u n d - s t a t es in t h er an g e$ 0 \leq X \leq 1/2 $, b u t o n eo f t h ese, a tX = 5/12, i s p r e d i c t e d t o d i s p r o p or t i o na t e a tT$ \approx 220K $. A tX$ \approx 1/3 ( $H f_{3} O$ ) and X $\approx 1/2 ($ Hf_{2}O$), order-parameter vs temperature plots predict Devil's Staircases of closely related ordered structures.

First Principles Phase Diagram Calculations for the Octahedral-Interstitial System HfOX​, 0≤X≤1/2

Abstract

First Principles Phase Diagram Calculations for the Octahedral-Interstitial System $H f O_{X}$ , $0 \leq X \leq 1/2$