Modulation-doped Al0.22Ga0.78N/GaN heterostructure with 1000 A Si-doped n-Al0.22Ga0.78N barrier (n-AlGaN) were deposited on (0001)-oriented sapphire (-Al2O3) by means of atmosphere-pressure metal-organic chemical vapor deposition. The reciprocal space mappings of symmetric reflection (0002) and asymmetric reflection (1014) were measured with high resolution X-ray diffraction. The results indicate that the microstructure and strain status of barrier correlate to that of the underlying i-GaN layer. The barrier holds an "abnormal" strainrelaxation status, which probably results from the internal defects of n-AlGaN and the strain relaxation status at the i-GaN/-Al2O3 interfaces. The results from grazing incidence X-ray diffraction show that the strain in barrier is nonuniform, which is consistent with the results from the reciprocal space mappings.

The magnetic and electrical properties of crystalline Mn0.05Si0.95 films prepared by post-thermal treatment of the as-deposited amorphous Si-Mn s95 at.%−5 at.%d have been investigated. Both the temperature dependence and field dependence of magnetization were measured using superconducting quantum interference devices, and it has been indicated that the film materials are ferromagnetic with Curie temperature over 400K. X-ray diffraction analysis revealed full crystallization of the films and the incorporation of Mn into the host crystalline Si lattice. Behavior of thermally activated conduction processes of the films has been evinced by electrical property measurement for the films.

Crystal tilts in the epitaxial lateral overgrown (ELO) GaN region over SiO2 mask by hydride vapor phase epitaxial away from the opening region were investigated by scanning electron microscope and the four-circle x-ray diffraction method. The increased mask width and ratio of stripe opening width to stripe period (fill factor) lead to increased wing tilts. The introduction of additional HCl and C3H8 /H2 can decrease wing tilts and improve the ELO GaN surface morphologies significantly. Moreover, it has been observed that a high growth rate will bring more defects and large wing tilts into the GaN materials.

y was observed in the interface width, that of the Si layer becoming very large. When this was observed, the measured Ge layer thickness was substantially less than the nominal thickness determined from the growth parameters. X-ray diffuse scattering easurements show that the topological roughness was small. The data are interpreted in terms of diffusion of Ge into the Si beneath the Ge layer, a modified Stranski–Krastanov growth mode resulting in the formation of a 3-dimensional "inverted hut" structure of Si-Ge islands. Grazing incidence X-ray scattering provides a rapid and non-destructive technique for the identification of the growth mode. 2003 Elsevier B. V. All rights reserved.

Si/Ta/Co/Cu/CoFeMn sor NiOd spin valves were prepared by a delayed sputtering procedure, in which depositions of Ta and followed layers were intervened by 1 h. The spin valves are found to have better coherent growth with stronger s111d preferred orientations in Co and Cu layers, compared with the traditional continuous method. At the same time, the giant magnetoresistance ratio and spin-dependent scattering are enhanced by a factor of 20%-30%. These results indicate that the coherent growth and the s111d preferred orientation can enhance the spin-dependent scattering of spin valves.