First-principles study on doping and phase stability of HfO2
First-principles study on doping and phase stability of HfO2
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DOI：
10.1103/physrevb.78.012102
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发表时间：
2008-07-01
影响因子：
3.7
通讯作者：
Han, Seungwu
中科院分区：
文献类型：
--
作者：
Lee, Choong-Ki;Cho, Eunae;Han, Seungwu
基于密度泛函方法，研究了HfO2在掺杂阳离子或氧空位时，单斜相、四斜相和立方相的相对稳定性。发现离子半径小于Hf的掺杂剂如Si、Ge、Sn、P、Al或Ti使四方相稳定，但使立方相不稳定。相比之下，较大的掺杂剂如Y、Gd或Sc有利于立方相。离子化氧空位补偿三价掺杂剂大大稳定立方相和四方相。并对实验结果进行了微观解释。每种掺杂剂所支持的亚稳相与实验数据吻合得很好。我们的研究结果可以作为一个有用的指导，在选择掺杂剂，以稳定特定的相。
Based on density functional methods, relative stabilities between monoclinic, tetragonal, and cubic phases of HfO2 with cation dopants or oxygen vacancies are investigated. It is found that dopants such as Si, Ge, Sn, P, Al or Ti with ionic radii smaller than Hf stabilize the tetragonal phase but destabilize the cubic phase. In contrast, larger dopants such as Y, Gd or Sc favor the cubic phase. The ionized oxygen vacancies compensating trivalent dopants greatly stabilize both cubic and tetragonal phases. Microscopic explanations on the results are also given. The metastable phase favored by each dopant is in good agreement with experimental data. Our results can serve as a useful guide in selecting dopants to stabilize a specific phase.