ISSN:0370-1972    

DOI:10.1002/pssb.2221930225

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221930226

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221930227

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221930228

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

ISSN:0370-1972    

DOI:10.1002/pssb.2221930229

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe gradual substitution of Cu by Ag in the Al62Cu25.5−xAgxFe12.5icosahedral phase (x≤ 10) is investigated by X‐ray diffraction from the viewpoint of the induced structural changes. The phonon and random phason disorders, estimated from diffraction linewidths, increase with x, the latter showing, however, an induction range of Ag concentrations. EXAFS results at the CuK and FeK edges show, for low Ag contents, and enhanced disorder in the first coordination sphere, partly relaxed for higher x values. The 6D hypercubic lattice parameter is found to be independent of the Ag content, despite the large diameter of monovalent Ag. The latter facts suggest a d‐sp hybridization of the Ag bonds to the surrounding Al, taking place above a certain

ISSN:0370-1972    

DOI:10.1002/pssb.2221930202

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe structure of YBaSiON glasses is investigated by neutron diffraction, and their physical and chemical properties are measured. It is found from the analysis of the radial distribution functions that nitrogen atoms exist as a mixture of two‐coordinated and three‐coordinated states in the glass, and the ratio of the three‐ to the two‐coordinated nitrogens decreases as the nitrogen content increases. The relationship between structure and properties is

ISSN:0370-1972    

DOI:10.1002/pssb.2221930203

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractPositron annihilation is measured for nickel containing defects carefully controlled by cold‐rolling, by further tempering, and by hydrogen doping. By the cold‐rolling the mean positron lifetime was increased from 123 to 179 ps corresponding to the formation of single vacancies and dislocations. The mean lifetime does not change significantly at further tempering. On hydrogen doping of the cold‐rolled sample a long lifetime component of about 390 ps appears, but a similar long lifetime component does not appear by hydrogen doping of the tempered sample. This suggests that hydrogen forms a composite with a vacancy which then becomes the center of vacancy agglomeration. The S‐parameter of the Doppler broadened annihilation radiation also shows changes completely in accordance with this interpr

ISSN:0370-1972    

DOI:10.1002/pssb.2221930204

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractThe experimental data on heat conduction of parahydrogen solid solutions with Ne and Ar impurities are analyzed. Specific relaxation mechanisms which may manifest themselves in strongly anharmonic crystals with resonantly scattering impurity centers are examined.

ISSN:0370-1972    

DOI:10.1002/pssb.2221930205

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY

摘要:

AbstractX‐ray powder diffraction, differential thermal analysis, and magnetic susceptibility measurements on polycrystalline samples are used to determine the details of the T(z) phase diagram of the alloy system Cu2(1−z)MnzGa2Se4. At high temperatures, there is a single phase solid solution across the complete diagram in a disordered zincblende phase. However, at lower temperatures, the singlephase range is limited to relatively wide terminal fields, which are ordered structures based on a zincblende subcell. Several different ordered phases are found to occur and the values of the Curie‐Weiss constant θ are used to investigate the changes in ordering with composition. It is shown that these ordering changes cause discontinuous changes in the slope of the graphs against composition of the lattice parameters, optical energy gap, and Néel temperature

ISSN:0370-1972    

DOI:10.1002/pssb.2221930206

出版商:WILEY‐VCH Verlag    

年代:1996

数据来源: WILEY