论文标题
\ b {eta} - （alxga1-x）2O3合金在Rietveld Analysis中确定\ b {eta} - （alxga1-x）2O3合金的确定
Determination of Al occupancy and local structure for \b{eta}-(AlxGa1-x)2O3 alloys across nearly full composition range from Rietveld analysis
论文作者
论文摘要
单斜\ b {eta} - （alxga1-x）2O3合金的Al占用和局部结构（键长和键角），已从X射线衍射数据的Rietveld细化中确定，含有高达90％的成分（x）。与四面体（TD）原子部位相比，Al Atom优先占据八面体（OH）原子位点。但是，大量的TD原子位点，即5％的Al组成的20％仍然被Al Atoms占据，发现随着Al组成的成分急剧增加。即使在90％的Al组成中，OH原子位点也没有被Al原子完全占据。 \ b {eta} - （alxga1-x）2O3合金减小（与Al组成线性增加（增加）的晶格参数（带隙）与Al成分线性地增加（增加），但是在近似于50％的Al组成下，晶格参数和带隙的变化变化的变化发生了变化。由于键角变化很大变化表明，发现该晶格的成分超过50％。晶格失真被确定为单斜\ b {eta} - （alxga1-x）2O3合金系统的晶格参数变化和带隙变化的斜率变化的来源。我们的结果为\ b {eta} - （alxga1-x）2O3合金的局部结构提供了见识，这些合金必须更好地了解其物理特性。
Al occupancy and local structure (bond length and bond angles) for monoclinic \b{eta}-(AlxGa1-x)2O3 alloys, with Al compositions (x) up to 90%, have been determined from Rietveld refinement of x-ray diffraction data. Al atom preferentially occupies octahedron (Oh) atomic site in comparison to tetrahedron (Td) atomic site. However, sizable number of Td atomic sites i.e. 20% for Al composition of 5% remain occupied by Al atoms, which is found to increase sharply with Al composition. The Oh atomic sites are not fully occupied by Al atoms even for Al composition of 90%. The lattice parameters (band gap) of \b{eta}-(AlxGa1-x)2O3 alloy decrease (increases) linearly with Al composition, but a change in slope of variation of both lattice parameters and band gap is observed at around Al composition of 50%. The lattice is found to be distorted for Al compositions more than 50% as indicated by large change in the bond angles. The lattice distortion is determined to be the origin for the observed change in slope for the variation of both lattice parameters and band gap for monoclinic \b{eta}-(AlxGa1-x)2O3 alloy system. Our results provide an insight in to the local structure of \b{eta}-(AlxGa1-x)2O3 alloys, which are required to have better understanding of their physical properties.
