Effect of Long-Term Heat Treatment on the Acceptor Behavior of Gold in Silicon

Data are presented on the electrical activity of Au in Czochralski Si heat-treated and diffusion-doped under various conditions. The results are interpreted in terms of force fields responsible for changes in the concentration of electrically active centers. Long-term heat treatment between 700 and 1050°C is shown to have a significant effect on the acceptor behavior of Au in diffusion-doped Si. The concentration of Au acceptors is sensitive to the surface condition in the course of heat treatment: a tungsten coating increases the Au concentration in the bulk of diffusion-doped Si.     

Assessment of the effectiveness of compaction of ShKh15 steel powders by hot extrusion

Conclusions Hot extrusion enables high-density steel to be obtained from an ShKh15 powder at a reduction = 2.15 (degree of deformation 33%). The strength of P/M ShKh15 steel after extrusion and annealing lies in the range 720–780 MPa, and thus surpasses the strength of the same steel produced by casting (650–700 MPa), while the ductility characteristics of the two steels are comparable.Translated from Poroshkoyaya Metallurgiya, No. 1(289), pp. 25–28, January, 1987.A 1.0% C-1. 5% Cr ball-bearing stell grade — Publisher.Deceased.     

Synthesis,X-ray structure analysis,and Raman spectroscopy of R<Subscript>2</Subscript>TiO<Subscript>5</Subscript>-based (R = Sc,Y) solid solutions

Order–disorder transitions in xR₂O₃ · (1 ? x)TiO₂ (R = Sc, 0.4 ≤ x ≤ 0.5; R = Y, 0.5 ≤ x ≤ 0.6) solid solutions with highly imperfect fluorite-derived structures have been studied using monochromatic synchrotron X-ray diffraction and Raman spectroscopy. The results demonstrate that the synthesis process leads to the formation of a fluorite-like (Fm3m) disordered phase and a nanoscale (~10–100 nm) pyrochlore-like (Fd3m) ordered phase of the same composition, coherent with the disordered phase. We have determined their lattice parameters. The Raman spectra of Sc₂TiO₅ (Y₂TiO₅) contain broad lines in low- and high-frequency regions: at 190, 350, and 775 (134, 188, 365, 404, and 727) cm^?1. These lines are characteristic of a pyrochlore-like phase with a varying degree of order and a disordered fluorite-like phase, respectively. The pyrochlore-like phase Y₂Ti₂O₇ has two strong Raman peaks in the low-frequency region: at 312 and 527 cm^?1. The formation of nanodomains with different degrees of order is caused by the internal stress that arises from the high density of structural defects in the unit cells of the solid solutions.     

A study of Xe 2β decay using the DEVIS tracking setup at the institute for theoretical and experimental physics

The DEVIS experiment aimed at searching for 2ν2β decay of ¹³⁶Xe isotope has been conducted for several years at the Institute for Theoretical and Experimental Physics. The DEVIS (DEtector for VISu-alization) tracking setup is a time projection chamber placed in a magnetic field. Xenon samples with a mass of 4 kg and different isotopic compositions have been sequentially exposed in it. An excess of events has been observed in the run with the sample enriched in ¹³⁶Xe. The stages of the experiment are described, and the background processes capable of simulating events of 2ν2β decay are analyzed. The limit on the half-life of ¹³⁶Xe 2ν2β decay is shown to be T _1/2 (2ν2β) > 2.1 × 10²⁰ years.