论文标题
划分的GA空缺和正电子歼灭光谱的异常强大各向异性，$ \boldsymbolβ$ -ga $ _2 $ o $ $ _3 $
Split Ga vacancies and the unusually strong anisotropy of positron annihilation spectra in $\boldsymbolβ$-Ga$_2$O$_3$
论文作者
论文摘要
我们报告了一项有关$β$ -GA $ -GA $ _2 $ o $ _3 $ lattice和GA单一缺陷缺陷的系统第一原理研究，并与依赖于方向依赖的实验的多普勒宽广的positron-electron-Electron-Electron-EnnihiLation的实验相互补。我们发现，$β$ -GA $ _2 $ o $ _3 $ lattice和所考虑的缺陷在其多普勒扩大信号中表现出异常强的各向异性。这种各向异性与$β$ -GA $ _2 $ o $ $ _3 $晶体结构的低对称性有关，即使在晶格中的Delailocalized状态下，也会导致正电子的一维限制。特别是，最近通过扫描透射电子显微镜观察到的分裂GA空位会产生异常各向异性正电子歼灭信号。我们表明，在实验中，$β$ -GA $ _2 $ o $ $ _3 $样品中的正电子歼灭信号似乎通常由拆分GA空缺主导。
We report a systematic first principles study on positron annihilation parameters in the $β$-Ga$_2$O$_3$ lattice and Ga mono-vacancy defects complemented with orientation-dependent experiments of the Doppler broadening of the positron-electron annihilation. We find that both the $β$-Ga$_2$O$_3$ lattice and the considered defects exhibit unusually strong anisotropy in their Doppler broadening signals. This anisotropy is associated with low symmetry of the $β$-Ga$_2$O$_3$ crystal structure that leads to unusual kind of one-dimensional confinement of positrons even in the delocalized state in the lattice. In particular, the split Ga vacancies recently observed by scanning transmission electron microscopy produce unusually anisotropic positron annihilation signals. We show that in experiments, the positron annihilation signals in $β$-Ga$_2$O$_3$ samples seem to be often dominated by split Ga vacancies.
