共查询到18条相似文献,搜索用时 185 毫秒
1.
2.
MBE[(GaAs)l(Ga1-λAlxAs)m]n/GaAS(001)一维超晶格的X射线双晶衍射测量 总被引:1,自引:1,他引:0
本文着重介绍了MBE[(GaAs)l(Ga1-xAlxAs)m]n/GaAs(001)一维超晶格的X射线双晶衍射测量方法。根据卫星峰的出现,证明超晶格的存在。基于超晶格的台阶模型和X射线衍射的运动学理论,推导出超晶格多结构参数的计算方法。并对X射线双晶给出的其他信息做了必要的讨论。 相似文献
3.
本文着重介绍了MBE[(GaAs)_l(Ga_(1-x)Al_xAs)_m]_n/GaAs(001)一维超晶格的X射线双晶衍射测量方法。根据卫星峰的出现,证明超晶格的存在。基于超晶格的台阶模型和X射线衍射的运动学理论,推导出超晶格多结构参数的计算方法。并对X射线双晶给出的其他信息做了必要的讨论。 相似文献
4.
5.
本文报导了用计算机控制的衍射仪(CuKα辐射)测量的金属有机化学汽相沉淀(MOCVD)方法生长的Ⅱ-Ⅵ族应变层超晶格的X射线衍射曲线,观察到了超晶格结构的多级卫星峰,且卫星峰的强度随角度呈周期性变化.对这种卫星峰形成包络的衍射曲线,用X射线运动学衍射理论进行了分析和讨论,这种讨论有助于理解X射线衍射曲线中卫星峰的形成.同时用光致发光和包络峰宽度的方法估算了样品的结构参数. 相似文献
6.
7.
8.
9.
10.
我们首次在透明衬底CaF2上生长了ZnSe-ZnTe应变超晶格。通过X射线衍射测量,观测到多级卫星峰,表明超晶格周期结构的形成.光致发光光谱峰值的蓝移,表征ZnSe-ZnTe超晶格中应变与量子尺寸效应的存在.吸收光谱中几个明显的拐点,表明了发生在超晶格导带与价带子能级之间的多级跃迁的形成。 相似文献
11.
12.
M.R.B. Forshaw 《Optics Communications》1975,15(2):218-221
The far-field diffraction patterns of overexposed thick holographic gratings often contain circular or arcuate structures. The geometrical properties of these patterns were explained earlier. This letter explains the fine-structure of the rings using an extension of the kinematical theory of X-ray diffraction. 相似文献
13.
在本文中,我们在经典的X光运动学理论的基础上,加入一些改进,不再直接计算超晶格的结构因子F00L,而是计算各原子面的散射波函数,获得了卫星峰的模拟峰形和pendell?sung条纹,克服了原来不能解释峰形和pendell?sung现象的缺点。本文还用此方法对GaAlAs/GaAs超晶格和GeSi/Si应变超晶格进行了模拟计算,与实验吻合很好,证明了理论的正确性。 相似文献
14.
The analysis of X-ray diffraction data forms an important non-destructive technique for the study of interdiffusion in multilayer structures. A frequently used approach is that of Fleming et al. in which the characteristic X-ray diffraction satellites from a superlattice structure are shown to be related to the corresponding Fourier components of the real space composition modulation. This relationship is derived assuming the strain to be small although the limitations on this parameter are unclear. To clarify this limitation the Fleming technique has been tested for a range of x values, and hence strain, using as examples a series of model multilayer CdTe:Cd1-xMnxTe structures. The approach has been to use a simulation technique based on the kinematical theory of X-ray diffraction to model the X-ray rocking curves from a series of structures in which the Mn diffusion profiles had been calculated using a particular value of the diffusion coefficient D. The values of the diffusion coefficient, derived from the diffraction data using the Fleming method, agree with the input D at low x values but differ for high x, high strain, structures and a criterion is suggested for the range of validity of the method. 相似文献
15.
16.
U. Van Bürck 《Hyperfine Interactions》1986,27(1-4):219-230
The main results of the kinematical theory and of the dynamical theory for resonant diffraction are summarised, with special
emphasis given to the coherent enhancement of the radiative channel and to the suppression of the incoherent channels. 相似文献
17.
Study of Ag/Si(111) submonolayer interface: II. Atomic geometry of Si(111) (√3 × √3 )R30°-Ag surface
Final state diffraction of Ag 3d X-ray photoelectrons from the Si(111) (√3 × √3)R30°-Ag surface has been measured. From a kinematical analysis of the diffraction patterns, it is found that a buried honeycomb framework of Ag atoms is formed on the surface with lateral displacement of the first Si layer. 相似文献
18.
J. Qin F. Xue L. Huang Y.L. Fan X.J. Yang Z.M. Jiang Q.J. Jia X.M. Jiang 《Surface science》2005,580(1-3):51-56
The surface segregation of phosphorus in silicon at low temperatures is studied by using δ doping structures grown by molecular beam epitaxy. The samples are characterized by X-ray crystal truncation rod (CTR) scattering using synchrotron radiation as the light source. The 1/e decay length of P segregation and segregation barrier energy are obtained by fitting the CTR curves within kinematical approximation of X-ray diffraction theory. The surface segregation of P is strong at a growth temperature of 450 °C, with a 1/e decay length of 14 nm, while for growth temperatures below 350 °C, P segregation is negligible with a 1/e decay length not larger than 4 nm. The segregation barrier energy is determined to be 0.43 eV. 相似文献