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

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

Materials Science 2011-07-28 v2

Authors: Benjamin P. Burton , Axel van de Walle

Abstract

First principles based phase diagram calculations were performed for the hexagonal closest packed octahedral-interstitial solid solution system $\alpha HfO_{X} ($ \alpha Hf[ ]_{1-X}O_{X} $; [ ]=Vacancy;$ 0 \leq X \leq 1/2 $). The cluster expansion method was used to do a ground state analysis, and to calculate the phase diagram. The predicted diagram has four ordered ground-states in the range$ 0 \leq X \leq 1/2 $, but one of these, at X=5/12, is predicted to disproportionate at T$ \approx 220K $. At X$ \approx 1/3 ( $Hf_{3}O$ ) and X $\approx 1/2 ($ Hf_{2}O$), order-parameter vs temperature plots predict Devil's Staircases of closely related ordered structures.

Keywords

first principles phase diagram cluster expansion ground state analysis octahedral interstitial solid solution hafnium oxide devil's staircase

Cite

@article{arxiv.1107.4318,
  title  = {First Principles Phase Diagram Calculations for the Octahedral-Interstitial System $HfO_{X}$, $0 \leq X \leq 1/2$},
  author = {Benjamin P. Burton and Axel van de Walle},
  journal= {arXiv preprint arXiv:1107.4318},
  year   = {2011}
}

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

Abstract

Keywords

Cite

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