Effect of impurity concentration on the cadmium density during cyclic thermal treatment

An experimental study was made of the effects of various concentrations of bismuth, lead, zinc, indium, and mercury on the density of cadmium during cyclic thermal treatment. Soluble eutectic impurities, like relatively insoluble impurities, can reduce the cadmium density during this treatment if the upper temperature of the cycle falls in the region of the solid-liquid state.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 1, pp. 79–84, January, 1970.Deceased     

Effect of multicomponent admixtures on the change of density of cadmium under cyclic thermal treatment

Investigations were conducted on the occurrence of voids under cyclic thermal treatment in high purity cadmium containing controlled eutectic additions (Sb, Cu, Bi, Sn, Pb). A study was made of the simultaneous effect of several elements, whose total concentration amounted to 0.05 wt.%, on the process of void formation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 33–37, 1972.     

Effect of cyclic heat treatment on the density of cadmium with a bismuth admixture

A study has been made of the effect of cyclic heat treatment on the density of cadmium having a bismuth admixture. The effects of the heating rate, cooling rate, and time the cadmium is held at the maximum temperature were studied. It is concluded that thermal-structural stresses and admixture enrichment of grain boundaries play an important role in the density changes.Deceased.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 12, No. 6, pp. 21–27, June, 1969.     

Effect of impurities on the thermal efficiency of a short-circuited generator

An analysis is made of the possibility of increasing the thermal efficiency Z_sh of a short-circuited anisotropic generator by doping with impurities and by choosing an optimum angular orientation. In an illustration it is shown that doping leads to an increase in Z_sh far beyond the value for an ordinary anisotropic generator. The calculated results are confirmed experimentally in a study of CdSb crystals doped with a silver acceptor impurity.Translated from Izvestiya VUZ. Fizika, No. 8, pp. 7–11, August, 1970.     

Effect of quenching temperature on pore formation during the cyclic heat treatment of aluminum

It has previously been shown [1] that pores are formed during the repeated heating and rapid cooling of commercially pure aluminum, and that as a result a deterioration in the mechanical properties of the material is observed. The fact that the intensity of pore formation increases with reduction in the diameter of the specimens being investigated — i.e., under conditions when the amount of plastic deformation decreases [2] and the rate of cooling, and consequently the concentration of quenching vacancies increases — leads to the assumption that the development of porosity observed in aluminum is due not to thermal stresses but to quenching vacancies.An approximate estimate of the number of fixed vacancies during repeated heat exchanges and comparison with the experimentally observed change in volume show that such an assumption is not without foundation.The present paper gives the results of further investigations into the behavior of aluminum under conditions of repeated sudden heat exchanges, and in particular the effect of quenching temperature, as a factor which increases the concentration of quenching vacancies, on the change in mechanical properties and microstructure of the material.     

Platinum-silicide formation during rapid thermal annealing: Dependence on substrate orientation and pre-implanted impurities

The kinetics of Pt-silicide formation during rapid thermal annealing has been studied as a function of silicon-substrate orientation ((111), (011), and (001)) and type of pre-implanted impurity in the silicon substrate (As, Kr, and Ge). Rutherford backscattering spectrometry, transmission electron microscopy, and four-point probe resistivity measurements were used for this investigation. In the case of Pt₂Si growth, both an orientation and impurity dependence was observed; the PtSi growth, however, was found to be independent of these parameters except in the case of As pre-implantation for which a retardation was found.     

Influence of impurities and thermal treatment on spectroscopic properties and laser performance of thulium-doped yttrium vanadate crystals

Influence of impurities and thermal treatment on spectroscopic properties and laser performance of thulium-doped yttrium vanadate crystals was examined. YVO₄ crystals nominally pure, single doped with Tm³⁺ and co-doped with Tm³⁺ and Ca²⁺ were grown by the Czochralski method and then thermally treated at 1150 °C for several hours in a reducing atmosphere (vacuum) or oxidizing atmosphere (air). Samples of crystals were investigated by nuclear magnetic resonance spectroscopy (NMR) and by optical spectroscopy methods. Laser performance of samples was examined upon laser diode pumping. For pure YVO₄ and for YVO₄ containing 0.5 at. % of Tm a single-site NMR spectrum of ⁵¹V nuclei was observed with central line widths of 2.5 and 3.2 kHz (FWHM), respectively. For samples containing 5 at. % of Tm the NMR spectrum was a superposition of multi-site spectra indicating at least three kinds of vanadium sites with axial symmetry. Optical absorption spectra did not contain bands that could be ascribed to V⁴⁺ ions in tetragonal sites. Level of matrix absorption in the visible region and its increase with decreasing wavelength from about 600 to 370 nm was found to be substantially dependent on conditions of thermal treatment. Thermal treatment of crystals and additional doping with Ca did not influence the ³ F ₄ lifetime of thulium and laser performance of crystals, however. Infrared absorption spectra revealed OH^- contamination in all samples. It has been concluded that the quenching of the ³ F ₄ emission in samples containing 5 at. % of thulium is related to migration-accelerated energy transfer to hydroxyl ions acting as energy sinks. PACS 42.55.Xi; 42.62.Fi     

Diffusion under periodic-supersaturation conditions during cyclic heat treatment

Conclusions The materials in which a tendency toward pore formation is observed during cyclic heat treatment are supersaturated with impurities at the low temperature of the cycle. The maximum supersaturation occurs in regions in which there is a high diffusion coefficient, particularly along grain boundaries. The impurities precipitated in these regions serve as crystallization centers for impurity diffusion from other regions. The pore formation can be thought of as the expansion of such regions and the enrichment of these regions with impurities and vacancies.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 126–128, November, 1970.     

Effect of thermal phase fluctuations on the superfluid density of two-dimensional superconducting films

High precision measurements of the complex sheet conductivity of superconducting a-Mo77Ge23 thin films have been made from 0.4 K through T(c). A sharp drop in the inverse sheet inductance, L-1(T), is observed at a temperature, T(c), which lies below the mean-field transition temperature T(c0). Just below T(c), the suppression of L-1(T) below its mean-field value indicates that longitudinal phase fluctuations have nearly their full classical amplitude, but they disappear rapidly as T decreases. We argue that there is a quantum crossover at about 0.94T(c0), below which classical phase fluctuations are suppressed.     

Effect of substrate impurities on layering transitions

We investigate the influence on thin film growth of substrate impurities distributed throughout the substrate bulk. In particular, using a method discussed in a previous paper, we show that the case of correlated disorder will enhance film growth via two mechanisms. Both the chemical potential, and the adatom-adatom interactions are effectively shifted in the intermediate temperature range, thus having the effect of encouraging film growth.     

Effect of impurities on superconduction in tin

Ultrasonic absorption peaks were observed in a single crystal of tin doped with 0.0093 at % indium. The results are discussed here.     

Combined effects of donor and acceptor impurities on the thermoelectric properties of cadmium antimonide

A study was made of the effect of the simultaneous doping with donor (Te) and acceptor (Cu, Ag, Au) elements on the thermoelectric properties of CdSb. Doping with tellurium changes the p-type conductivity of the CdSb crystals to an n-type conductivity with an impurity (Te) activation energy of E_d = (0. 11 ± 0. 01) eV. Doping with an acceptor impurity changes the energy of the donor level, by E_d = 0. 14 eV for doping with silver, by E_d = 0. 10 eV for doping with gold and by E_d = 0. 095 eV for doping with copper. It is shown that the type of conductivity and the thermoelectric properties of CdSb can be adjusted in the desired direction through simultaneous doping with two impurities.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 6, pp. 90–94, June, 1970.     

Structural modification of synthetic opals during thermal treatment

The density and porosity of synthetic opals with spheres 315 and 1000 nm in diameter were measured in relation to the annealing temperature. At annealing temperatures of up to 500°C, the seeming density and porosity remain almost unchanged. Then, at temperatures of up to 950°C, the density increases gradually and, accordingly, the porosity decreases due to the collapse of nanopores caused by the sphere substructure. As the annealing temperature increases further, the opal density increases sharply up to 2.22 g/cm³ (which corresponds to the density of amorphous silica) and the open microporosity due to the voids between spheres disappears. Differential thermal and thermogravimetric analyses showed that SiO₂ powders with particles with average size of 315 and 1000 nm can have, respectively, two-and three-level systems of micro-and nanopores.     

The electronic thermal conductivity of superconductors with paramagnetic impurities

We have measured the thermal conductivitiesK _s in the superconducting state andK _n in the normal state of (La_1–x RE_x) Al₂ single crystals (RE: Gd, Ce;x0.005) between 0.4 and 8 K. The lattice conductivity is small in the superconducting state above 0.5T _c and in the normal state and is independent of annealing. Annealing does, however, strongly depress the ratioK _s ^e /K _n ^e of the electronic thermal conductivities. We also report on a theory of the electronic thermal conductivity which describes the experimental results quantitatively. Interaction effects between impurities show up for the samples with the highest RE-concentration.Work performed within the research program of the Sonderforschungsbereich 125 Aachen/Jülich/Köln     

热处理温度对化学镀磁性ICF玻璃靶丸特性的影响

在300,700和1 000 ℃温度下,对化学镀Ni-P合金涂层后的磁性ICF玻璃靶丸进行热处理,通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）和振动样品磁强计（VSM）对热处理后化学镀ICF玻璃靶丸的结构、形貌和磁性能进行了表征。结果表明：化学镀ICF玻璃靶丸经过热处理后,Ni-P涂层晶化为晶态合金层,涂层的组成颗粒直径和磁性能随着热处理温度的升高而不断增加,可望用于磁悬浮实验研究。     

热处理温度对化学镀磁性ICF玻璃靶丸特性的影响

 在300,700和1 000 ℃温度下,对化学镀Ni-P合金涂层后的磁性ICF玻璃靶丸进行热处理,通过X射线衍射仪（XRD）、扫描电子显微镜（SEM）和振动样品磁强计（VSM）对热处理后化学镀ICF玻璃靶丸的结构、形貌和磁性能进行了表征。结果表明：化学镀ICF玻璃靶丸经过热处理后,Ni-P涂层晶化为晶态合金层,涂层的组成颗粒直径和磁性能随着热处理温度的升高而不断增加,可望用于磁悬浮实验研究。     

The temperature dependence of quadrupole interactions at cadmium impurities in Arsenic metal

We have performed time differential perturbed angular correlation measurements over a temperature range from 77 K to 763 K to investigate the static electric quadrupole interaction of¹¹¹Cd in rhombohedral Arsenic metal. The observed quadrupole interaction frequency decreases with increasing temperature and is consistent with the well knownT ^3/2 relation, valid for metals.     

Effect of inorganic metal ion impurities on lyoluminescence

It is observed that the intensity of lyoluminescence (LL) (the emission during the dissolution of irradiated crystals) is considerably enhanced in the presence of certain transition metal ions in low concentration, while the LL is quenched due to the presence of certain other transition metal ions. A detailed investigation is carried out to understand the effect of these metal ions and probable mechanisms are proposed.