[en] In this paper glass forming capabilities of chalcogenide glasses based on As²Se³ with T1²Se concentrations are discussed. The studies were made using the differential thermal analysis (DTA) technique. These studies show that the glass forming tendency of As²Se³ decreases as the concentrations of T1²Se molecules are increased. Also these studies show that with addition of T1²Se, the glass transition temperature Tsub(g) of As²Se³ decreases, suggesting a tendency for weaker bonding and hence less stability of T1-rich compositions. (author)

[en] The radial distribution analysis of amorphous carbon obtained from graphite is discussed. The various interatomic distances obtained were 1.44 A, 2.57 A and 3.8 A. The coordination numbers for the first, second and third coordination sphere for this form of amorphous carbon were noted to be 3.15, 10.7 and 16.5, respectively. Values of the interatomic distances and the coordination numbers were found to lie between those for graphite and diamond. (author)

[en] Structural modifications of Al thin films implanted with Mn⁺ ions at liquid-nitrogen-temperature (LNT) (∼77 K) were studied by X-ray powder diffraction. For each Mn concentration, strain and crystallite size were determined from X-ray line broadening. For room-temperature (RT) implantation, amorphization begins at approximately 1 at.% Mn by thermally activated local atomic rearrangements which lead to the formation of amorphous zones or clusters. At LNT, a supersaturated solid solution is formed at mean Mn concentrations below 5 at.% Mn. At higher Mn concentrations, amorphous clusters formed throughout the sample in regions where the strain level reached a threshold value at a critical Mn concentration of 8.5%. Present investigations suggest a preferential short-range migration of Mn atoms from the remaining crystalline material to amorphous regions formed at LNT causing an Mn depletion and partial recovery of the crystalline regions. The maximum value of the atomic displacements U_st was found to be 0.13 ± 0.01 A and the maximum value of the strain was (1.65 ± 0.15) x 10^-3. The lattice constant a₀ of the host (Al) lattice was found to decrease by about 0.13%

[en] The presence of surface effects has been detected by noting changes in photoconductivity for the same sample under test in air at normal room temperature and pressure and in vacuum. For all samples, it has invariantly been found that photo-sensitivity is increased by changing from an air to a vacuum surround. In order to investigate which of the atmospheric constituents was responsible for the change, the photoconductivity response spectrum of a thin film of amorphous As²Se³ was measured at room temperature (297K) in a flow of dry N², dry O² and H²O. No change in the photo-conductivity response spectrum was noted in the ambient of N² and O². However, water vapour was found to decrease the photo-sensitivity of As²Se³ and shift the photoresponse spectrum towards the lower wavelength side. These changes were found to be reversible in nature. (author)

[en] The amorphization process of this A1 films by successive implantation with Mn+ ions at RT and LNT was studied by X-ray diffraction and Rutherford backscattering. For each Mn concentration strain and crystallite size were determined from X-ray line broadening. For RT implantation amorphization sets in at approximately 1 at% Mn by thermally activated local atomic rearrangements which lead to the formation of amorphous clusters. At LNT, a supersaturated solid solution is formed at mean Mn concentration below 5 at %. At higher Mn concentrations amorphous clusters are formed throughout the sample in regions where the local strain level has reached a threshold value which occurs at a critical local Mn concentration of 8.5 at%. The results indicate a preferential short-range migration of Mn atoms from the remaining crystalline material toward the amorphous formed at LNT causing a Mn depletion and partial recovery of the crystalline regions. (author). 11 refs, 8 figs

[en] Structural studies of polycrystalline H_0.57 ReO₃ grown with age of ReO₃ placed in air for 2 1/2 years, at normal room temperature conditions, are reported. 13 refs, 1 tab

[en] The structural modifications of aluminium thin films implanted with manganese ions at room temperature, have been reported. These studies were performed using a two circle X-ray powder diffractometer. The method of X-ray line profile analysis was used to determine strain. As a consequence of ion bombardment, the aluminium lattice was found to undergo distortions. The maximum value of the atomic displacement U_st was found to be 0.14±0.01 A, and the maximum value of the root mean square strain was noted to be 1.05±0.15 x 10^-3. The lattice constant α₀ of Al was found to decrease. The decrease in α₀ was noted to be about 0.12 at %. (author). 23 refs, 10 figs

[en] A neutron detector is described which is suitable to be used in reactor cores and is characteristic for its radiation resistance and fast response time and furthermore is compatible with the materials in the reactor core. The construction consists of a detector insensitive to gamma radiation and high temperatures. The signal based on the magnetically focussed electrons is transferred from the core into regions of lower radiation doses, is amplified there and is recorded with radiation-sensitive components. (RW)

[en] X-ray fluorescence technique has been used for the analysis of Hf in the presence of Zr by developing a method. In this method the spectral interference of Hf lines by Zr is eliminated completely and the Hf detection is accomplished using the most efficient Li line of its L-series. The principle of the method is based on the extinction properties of crystals for some orders of reflection. Ge(III) is used as the analyzing crystal. This method can be used accurately to detect Hf in any concentration of Zr at least from about 20 ppm to 100%. Also no information about the expected range of the analyte sample, is required in advance. (authors)

[en] Structural modifications of Al thin films implanted with Mn ions at room temperature have been studied using a two-circle X-ray powder diffractometer. The method of X-ray line profile analysis was used to determine the strain. As a consequence of ion bombardment, the Al lattice undergoes distortions. The maximum value of the atomic displacement U_st was found to be 0.14±0.01 A, and the maximum value of the r.m.s. strain was (1.05±0.15) x 10^-3. The lattice constant a₀ of Al was found to decrease by about 0.12 at.%. (author)