单斜晶系
材料科学
四方晶系
掺杂剂
结晶学
电子结构
价(化学)
晶体结构
凝聚态物理
物理
兴奋剂
化学
光电子学
量子力学
作者
Richard G. French,S. Jill Glass,Fumio S. Ohuchi,Yong Xu,Wai-Yim Ching
出处
期刊:Physical review
日期:1994-02-15
卷期号:49 (8): 5133-5142
被引量:465
标识
DOI:10.1103/physrevb.49.5133
摘要
The addition of suitable dopants to ${\mathrm{ZrO}}_{2}$ can induce dramatic phase stabilization, and this dopant-induced phase stabilization is the basis of transformation toughening of zirconia-based structural ceramics. We have determined the electronic structure of three phases of ${\mathrm{ZrO}}_{2}$, cubic, tetragonal, and monoclinic, using vacuum-ultraviolet and x-ray-photoemission spectroscopies, coupled with ab initio band-structure and optical property calculations using the orthogonalized linear-combination-of-atomic-orbitals method, in an attempt to understand the complex interaction of the stabilizing dopants and associated atomic defects with the crystal structures of ${\mathrm{ZrO}}_{2}$ and their phase transitions. The experimental samples were single or polycrystalline stabilized materials which contain atomic defects, while the calculations were performed for undoped idealized ${\mathrm{ZrO}}_{2}$ structures without atomic defects. Reasonable agreement is found between experiment and theory at this level. The primary difference among the three phases of ${\mathrm{ZrO}}_{2}$ is the hybridization or mixing of the Zr 4d (${\mathit{x}}^{2}$-${\mathit{y}}^{2}$ and ${\mathit{z}}^{2}$) and the Zr 4d (xy, yz, and zx) bands, which form the conduction bands as the symmetry decreases from cubic to monoclinic. This leads to a complex evolution of the O 2p to Zr 4d and the O 2s to Zr 4d interband transitions. In addition, in the real materials, the presence of yttrium stabilizer introduces additional Y 4p valence bands and Y 4d conduction bands. The effective coordination of zirconium by oxygen is reduced from eightfold to sevenfold by the presence of the stabilizing ions and defects and this leads to the introduction of an occupied Zr 4d valence band suggestive of the presence of ${\mathrm{Zr}}^{2+}$.
科研通智能强力驱动
Strongly Powered by AbleSci AI