X-ray diffraction from one-dimensional superlattices in GaAs1−xPx crystals; erratum
X-ray diffraction from one-dimensional superlattices in GaAs1−xPx crystals; erratum
复制标题
GaAs1−xPx 晶体中一维超晶格的 X 射线衍射；
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
A. Blakeslee
中科院分区：
文献类型：
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作者：
A. Segmüller;A. Blakeslee
用x射线衍射分析了在砷化镓衬底上交替沉积GaAs和GaAs0.5P0.5层生长的超晶格晶体。成分的周期性变化导致沿生长方向的一维周期性晶格畸变。周期性晶格畸变产生的卫星峰接近砷化镓闪锌矿型晶格的布拉格反射。采用两种模型计算x射线衍射强度：一种模型用两个频率为ω = 0的纵向声子描述晶格畸变，另一种模型用周期阶跃函数描述晶格畸变。两个样品的x射线衍射数据表明，两个不同组成的交替层是相干的，因此构成了一个单晶，沿生长方向其单位晶胞大（g 100 A）。从两个模型与数据的拟合可以确定晶格畸变的周期和幅度、两层的相对厚度和相干衍射域的大小。讨论了这些参数与物理生长条件的关系。
An X-ray diffraction analysis has been performed on superlattice crystals which were grown epitaxically by alternately depositing GaAs and GaAs0.5P0.5 layers on a gallium arsenide substrate. The periodic change of compositions causes a one-dimensional periodic lattice distortion along the direction of growth. The periodic lattice distortion gives rise to satellite peaks close to the Bragg reflections of the sphalerite-type lattice of gallium arsenide. Two models are employed to calculate the X-ray diffraction intensities: in one the lattice distortion is described by two longitudinal phonons with frequency ω = 0, in the other a periodic step function is used. The X-ray diffraction data obtained on two samples show that the two alternating layers of different composition are coherent and, therefore, constitute one single-crystal with its unit cell large (g 100 A) along the growth direction. From the fit of the two models to the data one can determine the period and amplitude of the lattice distortion, the relative thickness of the two layers and the size of the domains which diffract coherently. These parameters are discussed in relation to the physical growth conditions.