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The effect of lateral oxidation on microstructures of the GaAs/AlAs/GaAs heterostructure was studied by x-ray specular reflectivity, nonspecular scattering and diffraction. The GaAs/Al2O3/GaAs multilayer was obtained after oxidation of the GaAs/AlAs/GaAs sample. The results show that, before oxidation, there are two 40-A-thick intermixing layers, one located between the AlAs sublayer and the GaAs substrate, and the other between the AlAs sublayer and the upper GaAs sublayer. After oxidation, these two intermixing sublayers disappear. The AlAs was oxidized into amorphous Al2O3 totally. The surface and interface roughnesses of the sample also decrease after oxidation.

The dislocations in lithium tetraborate crystal have been investigated by means of synchrotron radiation white beam topography in BSRL (Beijing Synchrotron Radiation Laboratory). The Burgers' vectors of these dislocations are determined by their vanishing conditions. Both screw and edge dislocations exist in the specimen.

The effect of Sb on Ge epilayer grown on Si(001) is investigated in situ by RHEED and ex situ by X-ray diffraction.Without Sb,island formation takes place when Ge epilayer is 6nm thick,and the strain in Ge epilyer is totally relaxed.With Sb,the growth mode of Ge on Si is two- dimensional, and the strain is relaxed gradually.Even if the thickness of the Ge epilayer is 6nm, 42%- strain is still not relaxed.

A AlAs/GaAs/AlAs/AlGaAs double-barrier superlattice grown on GaAs substrate by MBE has been studied by combining double-crystal X-ray diffraction and synchrotron radiation. This combination provides a comprehensive structural analysis. During simulated by X-ray dynamical diffraction theory, we find the intensity of satellite peaks which situated near-by the modulated wave point of one layer are very sensitive to the variation of the layer's structural parameters. Accoding to these, the accurate layer thickness can be get with an error less than 0.1nm. The modulated phenomenon is investigated by X-ray kinematical diffraction theory.

ＰｂＴｉＯ３ thin films were deposited on (001) redoping n-Si, (001) SrＴｉＯ３ substrates by low-pressure MOCVD technique, XRD θ－２θ scan shows that the film on Si substrate has a polycrystalline structure, while the other two films have preferential orientations and their epitaxial nature was confirmed by the X-ray φ scan, rocking curves of the two epitaxial thin films were taken at BSRF using the synchrotron radiation. The film on LaAlＯ３ substrate has an a,c domain coexisting structure, and the film on ＳｒＴｉＯ３ substrate only has a c-orientation. All the films exhibit a c-axis shortening compare with the bulk material, and the reason can be attributed to the size effect and surface influence. The ferroelectric properties of the polycrystalline thin films were investigated using the redoping Si substrate as bottom electrode directly, and the ＰｂＴｉＯ３ thin film shows a perfect hysteresis loop.

Variation of the correlation length of icosahedral phase with the annealing temperature is got according to the broadening of the x-ray diffraction peak. The fact that the correlation length does not change during the crystallization process means that the grains of icosahedral phase are transformed wholly and perfectly to crystalline Al6Mn.

The broadening of x-ray diffraction peaks has been used successfully to measure the grain sizes of WSi2 in cosputtered W-Si films after annealing. The grain size of WSi2 increases with annealing temperature and reaches 115nm afrer annealing at 1000°C. The grain sizes are quite similar to that obtained by transmission electron microscope in electron beam coevaporated film and low pressure chemical vapor deposited film.

The behaviors of amorphous W/C periodic multilayers after annealing have been studied by precise low-angle X-ray diffraction. Afte refraction correction, the period of multilayers can be calculated more accurately using th low angle peaks. The period increases with increasing annealing temperatures. The intensities of 2nd and 3rd Bragg diffraction also increase with the annealing temperatures. These phenomena can be interpreted by the increase of thickness of the carbon layers.

Using X-ray diffractometer equipped with a premonochromator, X-ray Huang diffuse scattering from defects in γ irradiated LiF crysial has been measured with differential and integral methods. The results show that the strain field of irradiation defects in LiF crystal is nearly isotropic.

The X-ray diffraction patterns of a Fibonacci series consisted of two kinds of atoms have been simulated according to the amplitudes summed up with phases. Peaks appeared at K=(m+nt)/(1+2t)d-1, where d is the average planar distance. Relationship between the anglewidth β of diffraction peaks and the total thickness of atomic layers obeys the Scherrer for-mula: β=(0.88λ)/(Dcosθ), just as that for crystals. The intensities of weak diffraction peaks ch-anged irregularly with the increasing number of atomic layers, which can be illustrated by zigzag path in the amplitude-phase diagram.