[en] A new phase transition in solid K-Cs solutions was investigated by both thermal and electrical resistivity measurements in the temperature range 110 to 340 K. The intermetallic compound K₂Cs was detected and its coexistence curve with the two-phase mixed crystals was traced between the concentrations 10 and 55 at% Cs. The heat of ordering of K₂Cs was measured: ΔH = 280 cal/mol. (author)

No abstract available

[en] X-ray-absorption fine structure (XAFS) and x-ray-diffraction (XRD) measurements of disordered alloys Au_xCu_1-x and Au_0.5Ag_0.5 prepared by melt spinning were performed. In the Au_0.5Ag_0.5 alloy, no significant local deviations of the atoms from the average fcc lattice were detected while in Au_xCu_1-x alloys, significant deviations of atoms from the average fcc lattice were found. Mean-square vibrations of the Cu-Cu distances revealed by the XAFS in Au_xCu_1-x alloys indicate the weakening of contact between Cu atoms in the dilute limit. Our computer simulation for Au_xCu_1-x clusters of 10⁵ atoms reproduces the main features of both the XAFS and XRD data

No abstract available

[en] Short communication

[en] Short communication

[en] Short communication

[en] The impedance of a circuit including an HTSC film as a function of temperature and frequency has been measured, and the presence of an intrinsic reactance in the HTSC films has been shown. The equivalent scheme of the measuring circuit has been synthesized, and the temperature dependence, type, and value of the HTSC-film reactance have been determined in the transition region near T_c. It is shown that the change of reactance sign with temperature observed earlier by a number of researchers and attributed to the intrinsic property of HTSC-film reactance was rather the result of the T-independent parasite reactive elements while the film impedance was becoming small. 5 refs., 3 figs

[en] X-ray absorption fine structure (XAFS) measurements of mixed salts Rb_xK_1-xBr and RbBr_yCl_1-y at their congruent melting points compositions reveal that their actual structure buckles about the NaCl average structure with an rms angular deviation from collinearity of 7--9 degree. XAFS measures the buckling directly through three-body correlations, and verifies the homogeneity and randomness of the mixtures. The characteristic ionic sizes are found to be dependent on concentration, causing changes to 0.1 A in interatom bond distances. A computer simulation based on the information from XAFS and diffraction displays the actual structure of the salts

[en] X-ray-absorption fine-structure (XAFS) measurements of metallic glass Al_0.91La_0.09 and a crystalline phase Al₁₁La₃ formed by annealing of the glass were made at the La L₃ edge and analyzed by the splice method. The first-neighbor partial radial distribution functions about the La atoms for the crystal and glass were obtained at T=12 K demonstrating the difference between their local structures. The shortest La-Al distance (mean value 3.09±0.05 A) within the glass was distinctively smaller than within the crystal Al₁₁La₃ (3.21±0.05 A). This partial shortening of the La-Al bonds decreases the size mismatch between the La and Al atoms making the glass formation more favorable with anomalously low content of La during the quench. Monte Carlo simulations were performed for the Al-La glass and agreement with the XAFS result was obtained. copyright 1996 The American Physical Society