Structural and magnetic properties of Cr<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>V<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Te (<Emphasis Type="Italic">x</Emphasis> = 0−0.4) solid solutions

Cr_1?x V _x Te solid solutions with a hexagonal structure (NiAs type) have been obtained in the composition range x = 0?0.4 by direct melting of elemental mixtures, followed by annealing and quenching. The 80-K magnetic moment is found to decrease from 2.4μ_B in CrTe to 1.52μ_B in Cr_0.6V_0.4Te. The Curie temperature varies from 342 K to 321 K, respectively.     

Thermal conductivity of Er<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Sn<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Se (<Emphasis Type="Italic">x</Emphasis> ≤ 0.025) solid solutions

The thermal conductivity of Er _x Sn_{1 ? x} Se solid solutions has been measured at temperatures from 80 to 360 K. The results have been used to evaluate the electronic and lattice components of thermal conductivity for elastic carrier scattering, parabolic bands, and arbitrary degeneracy. With increasing erbium content and temperature, both the electronic and lattice components decrease considerably. Long-term annealing increases both components. It follows from the present experimental data that heat conduction in Er _x Sn_{1 ? x} Se is mainly due to phonons and that the observed rise in thermal resistance with Er content is due to phonon-phonon and paramagnetic-ion scattering.     

Hydrochemical synthesis of AgCl<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Br<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions

A phase-component model is proposed for the hydrochemical conversion of silver chloride to AgCl _x Br_{1 − x} solid solutions, and the corresponding quantitative relations are derived. Experimental data are used to obtain a relation between the equilibrium composition of solid solutions and that of the liquid phase at different temperatures. The possible mechanisms of solid-solution formation are considered.     

Lattice parameter of PbTe<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Cl<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions

The lattice parameter of PbTe_1?x Cl _x solid solutions is shown to be a nonmonotonic function of chlorine content, with a minimum at x = 0.005. The results are interpreted in terms of a self-compensation model.     

Growth and properties of single crystals of Si<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> (0 < <Emphasis Type="Italic">x</Emphasis> < 0.35) solid solutions

Single-crystalline Si_{1 − x} Ge _x ingots with a germanium content of up to 35 at. %, a diameter of 10mm, and a length of up to 10 cm were grown using the crucibleless float-zone melting technique. The ingots had a homogeneous distribution of germanium and a low density of dislocations. The material was characterized with respect to the structure and electrical properties. The resistivity and the carrier lifetime, mobility, and concentration in Si_{1 − x} Ge _x single crystals have been studied as functions of the germanium content.     

Synthesis and structural properties of AgCl<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Br<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> (<Emphasis Type="Italic">x</Emphasis> = 0.5–0.8) solid solutions

The properties of AgCl_{1 - x} Br_x ( x = 0.5-0.8) solid solutions prepared by the Bridgman-Stockbarger method are studied using a variety of techniques (x-ray diffraction, microstructural examination, chemical analysis, and x-ray microanalysis). The lattice parameter of the solid solutions is found to exhibit a negative deviation from additivity. The effects of composition and preparation conditions on the structural properties of the solid solutions are discussed. The structural characteristics of abrasively polished surfaces of the samples are shown to be influenced by the preparation conditions.Translated from Neorganicheskie Materialy, Vol. 41, No. 1, 2005, pp. 78–87. Original Russian Text Copyright © 2005 by Artjushenko, Baskov, Golovanov, Kuzmicheva, Lisitskii, Musina, Polyakova, Sakharov, Sakharova.     

Phase diagram of the Pb-NiSb system and properties of (NiSb)<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Pb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions

The phase diagram of the Pb-NiSb system is presented. The system is pseudobinary, with a limited series of NiSb-based solid solutions: ≃1 mol % Pb at 300 K. In the temperature range ≃520–670 K, the system contains un unstable compound, Ni₃Pb₂Sb₃. At 1320 K, a monotectic transformation occurs (≃15–71 mol % NiSb). Electrical and thermal conductivity measurements reveal an additional contribution to the lattice thermal resistivity of the (NiSb)_{1 − x} Pb _x solid solutions and show that electrons and phonons in these materials are scattered elastically.     

Low-temperature heat capacity of Li<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Ni<Subscript>2 − <Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>2</Subscript> solid solutions

The heat capacity of Li _x Ni_{2 − x} O₂ (x = 0.40–0.76) oxides has been measured using an adiabatic calorimeter, and their thermodynamic functions have been determined. The results indicate that the lithium nickelate solid-solution series contains a two-phase region and that near-stoichiometric LiNiO₂ has a layered structure, in accordance with earlier results.     

A model for calculating the composition of GaAs<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>P<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions under metalorganic vapor phase epitaxy conditions

A model is proposed for calculating the composition of GaAs _x P_1–x solid solutions, based on the iterative determination of the equilibrium partial pressures of the pyrolysis products of the starting reagents, followed by calculation of the composition of the solid solution in an adsorption–desorption model. The proposed model ensures good agreement between calculation results and experimental data.     

Properties of YBaCuFe<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Ni<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>5</Subscript> (0 < <Emphasis Type="Italic">x</Emphasis> ≤ 0.3) solid solutions

YBaCuFe_{1 – x}Ni_xO₅ solid solutions are shown to exist for x 0.3. Data are presented on the lattice parameters, thermal stability, thermal expansion, electrical conductivity, thermoelectric power, magnetic susceptibility, and dielectric properties of the solid solutions. Ni substitution for Fe notably increases the electrical conductivity of the solid solutions, reduces their thermoelectric power and thermal expansion, and shifts the antiferromagnetic—paramagnetic phase transition and dielectric anomalies in YBaCuFe_{1 – x}Ni_xO₅ to lower temperatures.Translated from Neorganicheskie Materialy, Vol. 40, No. 12, 2004, pp. 1515–1519.Original Russian Text Copyright © 2004 by Chizhova, Klyndyuk, Bashkirov, Petrov, Makhnach.     

Heat capacity of Li<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Ni<Subscript>2 − <Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>2</Subscript> solid solutions

We have synthesized Li _x Ni_{2 − x} O₂ oxides in the range x = 0.1–0.84 and showed that the solid-solution system contains a two-phase region. The heat capacity of Li _x Ni_{2 − x} O₂ has been determined by differential scanning calorimetry.     

Thermal conductivity of TlIn<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Dy<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Te<Subscript>2</Subscript> solid solutions

The thermal conductivity of TlIn_{1 ? x} Dy _x Te₂ solid solutions, based on the compound semiconductor TlInTe₂, has been measured as a function of temperature (80–350 K). The results have been used to assess the effects of phonon-phonon and impurity scattering on the thermal conductivity of the solid solutions. Phonon scattering by the isovalent impurity Dy is shown to be significant above the Debye characteristic temperature of the materials.     

PbTe-VTe<Subscript>2</Subscript> phase diagram and properties of (PbTe)<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>(VTe<Subscript>2</Subscript>)<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions

The T-x phase diagram along the PbTe-VTe₂ join of the Pb-V-Te system has been studied. Vanadium-doped lead telluride crystals have been grown, and the longitudinal vanadium and carrier profiles in the crystals have been investigated. The temperature dependences of resistivity for the crystals lend support to the conclusion drawn earlier that PbTe〈V〉 is in a semi-insulating state at low temperatures. The crystals offer a high 20-K electron mobility, on the order of 10⁵ cm²/(V s), which attests to high electrical homogeneity of the material and stabilization of the Fermi level.     

Antireflection properties of diamond-like carbon films on Cd<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Zn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Te (<Emphasis Type="Italic">x</Emphasis> ∼ 0.04) single crystals

The optical properties of diamond-like carbon (DLC) films obtained by plasmachemical deposition on Cd_{1 − x} Zn _x Te (x ∼ 0.04) single crystals have been studied by ellipsometry. The ellipsometric data have been interpreted within the framework of a three-layer model of the DLC film-semiconductor crystal refractory system with transition layers between the film and substrate. It is found that DLC films exhibit antireflection properties in this refractory system in the IR spectral range. It is established that the proposed antireflection film-substrate structure is stable with respect to thermal cycling and ultrasonic treatment.     

Effect of growth conditions on the compositional homogeneity of Cd<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Zn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Te crystals

A crystal growth unit has been designed for Cd_{1 − x} Zn _x Te growth by the axial-heat-flux-close-to-the-phase-interface (AHP) method at argon overpressures of up to 12 MPa. The influence of melt superheating, growth rate, melt layer thickness, argon pressure, and growth mode on the Zn distribution in 21- to 45-mm-diameter crystals and defect formation in Cd_{1 − x} Zn _x Te ingots has been investigated. The results demonstrate that the AHP method offers the possibility of effectively controlling the shape of the solid-liquid interface and ensures low fluid velocity and high radial compositional homogeneity. The feeding method used markedly improves the axial Zn profile and ensures low dislocation density (5 × 10³ cm⁻²) in the grown crystal.     

Spectral sensitivity of (Si<Subscript>2</Subscript>)<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>(CdS)<Subscript>x</Subscript> solid solutions

Epitaxial layers of n-type solid solutions of the (Si₂)_{1 ? x} (CdS)_x system (0 ≤ x ≤ 0.01) were grown by liquid phase epitaxy from a tin-based solution melt confined between two horizontal p-type single crystal silicon substrates. The photosensitivity spectra of p-Si/n-(Si₂)_{1 ? x} (CdS)_x structures have been measured. A photoresponse peak at E ≈ 2.35 eV (1.25 eV below the top of the valence band of silicon) has been observed, which is probably related to an impurity level due to CdS molecules.     

Properties of amorphous Si<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Ge<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>:H (<Emphasis Type="Italic">x</Emphasis> = 0−1) films

Plasma deposition has been used to grow Si_1?x Ge _x :H(x= 0 ? 1) films, undoped and doped with PH₃ or B₂H₆, for p-i-n solar cells and other optoelectronic applications. The optical, electrical, and photoelectric properties of the films have been studied at constant hydrogenation and doping levels. The films deposited under appropriate conditions are amorphous, and three-layer solar cells fabricated from such films offer an efficiency of 9.5% at an illumination of 100 mW/cm². The photoresponse of the a-Si_{1 ? x} Ge _x :H films strongly depends on Ge content. The hydrogen concentration in the films was controlled by varying the gas phase composition and was determined from the IR absorption in the films.     

Negative temperature coefficient thermistor based on BaFe<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Sn<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>3−ε</Subscript> solid solutions

A negative temperature coefficient (NTC) thermistors based on BaFe _x Sn_1−x O_3−ε were fabricated by conventional solid-state reaction method. The microstructure and electrical properties of the NTC thermistors were characterized by X-ray diffraction (XRD), electric (R(T)), and impedance measurements. The XRD analysis shows that the BaFe _x Sn_1−x O_3−ε still remains cubic perovskite structure and the crystal growth orientation changes at higher Fe content. Similarly, the electric measurements indicates that all the samples show typical NTCR behavior; with increasing Fe content, the room temperature resistivity, activation energy, and thermistor constant decrease, are in the range of 2.52–217 KΩ cm, 0.343–0.43 eV, and 3900–4896 K, respectively. The impedance spectroscopy confirms that the observed ac resistance, consisting of the grain bulks, grain boundaries, and electrode–ceramic interface, mainly attributes to the grain boundaries and grain bulks; with the rise in temperature the grain boundary resistance shows more rapid change than the grain resistance; moreover, the Fe concentration can greatly affect the grain and grain boundary resistance.     

Formation of interfacial CdTe<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>S<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> solid solutions in CdTe/CdS heterojunctions

Experimental evidence is presented that interfacial CdTe_1?x S _x solid solutions graded in composition can be formed in CdTe/CdS heterojunctions.     

Optical and transport properties of Fe-doped Cd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Hg<Subscript>1−<Emphasis Type="Italic">x</Emphasis></Subscript>Se (<Emphasis Type="Italic">x</Emphasis> = 0.35)

The optical and transport properties of Fe²⁺-doped Cd _x Hg_1?x Se crystals with a midgap Fe²⁺ level have been studied. The results demonstrate that Fe²⁺ ions influence both the optical and transport properties of Cd _x Hg_1?x Se〈Fe²⁺〉. The observed optical absorption bands are due to a donor Fe²⁺ level in the band gap, with a depth E _Fe = 0.21 eV, and to band-band transitions. Thermal anneals in Hg and Se vapors have different effects on the carrier concentration and mobility in the crystals. The effect of annealing on the transport properties of the Fe²⁺-doped crystals differs from that for undoped crystals and is governed by the state of point defects.