B. Liautard

Phase diagram equilibria In2Se3-Sb2Se3 crystal growth of the β-In2Se3 phase (In1.94Sb0.06Se3)

Abstract The phase diagram In2Se3–Sb2Se3 was constructed from DTA and X-ray diffraction analysis data. No compound was observed in it, but two finite regions of In2Se3-based solid solutions were found: the first one, called β′ (from 10 to 3.5 mol% Sb2Se3), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb2Se3) being the β-In2Se3 stabilized form. Crystals of the antimony-doped β-In2Se3 form were grown by the Bridgman method. This compound, the composition of which is In1.94Sb0.06Se3, appears to be closely connected with the tetradymite structure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature dc conductivity is 2 × 10−2 Ωcm−1, and it is an n-type semiconductor with a band gap of 1.34 eV.The phase diagram In{sub 2}Se{sub 3}-Sb{sub 2}Se{sub 3} was constructed from DTA and X-ray diffraction analysis data. No compound was observed in it, but two finite regions of In{sub 2}Se{sub 3}-based solid solutions were found: the first one, called {beta}{prime} (from 10 to 3.5 mol% Sb{sub 2}Se{sub 3}), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb{sub 2}Se{sub 3}) being the {beta}-In{sub 2}Se{sub 3} stabilized form. Crystals of the antimony-doped {beta}-In{sub 2}Se{sub 3} form were grown by the Bridgman method. This compound, the composition of which is In{sub 1.94}Sb{sub 0.06}Se{sub 3}, appears to be closely connected with the tetradymite structure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature dc conductivity is 2 {times} 10{sup {minus}2} {Omega}/cm, and it is an n-type semiconductor with a band gap of 1.34 eV.

Solid state demixing in Bi2Se3-Bi2Te3 and Bi2Se3-In2Se3 phase diagrams

Abstract The Bi 2 Te 3 -Bi 2 Se 3 and Bi 2 Se 3 -In 2 Se 3 systems were studied by differential thermal analysis and X-ray powder diffraction. The phase diagrams of these systems were constructed; they are quasi-binary. In both cases, there are wide ranges of solid solutions based on the terminal compounds and an intermediate range of demixing. The solid solutions are of tetradymite type (rhombohedral R 3 m). Their limits are related to the substitution of the selenium-tellurium and bismuth-indium atoms in the layers. Electrical conductivity and thermoelectric power measurements confirm the boundaries of the solid solution regions deduced from the thermal and X-ray diffraction data.

The ternary system silver-antimony-tellurium. Study of the subternary Sb2Te3-Ag2Te-Te

Abstract The Sb 2 Te 3 -Ag 2 Te-Te subternary system was investigated using thermal analysis, differential scanning calorimetry metallographic technics and X-ray powder analysis. Three isopleth sections were constructed. The transitory reactions were characterized and the eutectic point coordinates were determined. Analysis of polythermal projection of this system is given.

Equilibres de phases dans le systeme tellurure de cuivre, tellurure de bismuth

Abstract The phase diagram of the binary Cu 2 Te-Bi 2 Te 3 system was determined by x-ray and DTA measurements. In a first time the successive phase transitions of the Cu 2 Te composition have been confirmed as well as its structural modifications as a function of the temperature. As the result, it has been shown that the terminal Bi 2 Te 3 based solid solution is nonexistent. The electronic doping character of the copper atoms is emphasised and some electric transport properties have been measured.

Differential thermal analysis under high hydrostatic pressures. Application to determination of phase diagram of semiconductors

Abstract In order to determine the melting curve of different materials under high gas pressures, a system for differential thermal analysis has been developed. A gas compressor with three stages of compression allows us to obtain pressures up to 1.5 GPa. The furnace in which the test material and the reference (boron nitride) are placed can operate up to 1000°C. This equipment was used at first to determine the melting curve of mercury telluride: the melting point decreases with pressure, and the slope of the melting curve is close to that reported in the literature, but the phase transition from zinc blende to cinnabar (B3 → B9) was not observed in our pressure range. This equipment was later used to study the influence of iron doping on the liquidus. The melting point, which was slightly lower in this case, also decreased with pressure.

Etude des equilibres de phases dans le systeme Cu2Se Bi2Se3. Caracterisation des composes intermediaires

Abstract The Cu 2 Se  Bi 2 Se 3 system is investigated using thermal analysis, differential scanning calorimetry, X-Ray powder diagrams and single crystal analysis. Two limited solid-solutions, Cu 2 Se and Bi 2 Se 3 based, are observed at high temperature. Two incongruently melting compounds are formed in this system: Cu 3 BiSe 3 and Cu 1,6 Bi 4,8 Se 8 . Crystallographic studies on these two phases are performed and lattice characteristics deduced.

Original ArticlesPhase Diagram Equilibria In2Se3–Sb2Se3 Crystal Growth of the β-In2Se3 Phase (In1.94Sb0.06Se3)

Abstract The phase diagram In2Se3–Sb2Se3 was constructed from DTA and X-ray diffraction analysis data. No compound was observed in it, but two finite regions of In2Se3-based solid solutions were found: the first one, called β′ (from 10 to 3.5 mol% Sb2Se3), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb2Se3) being the β-In2Se3 stabilized form. Crystals of the antimony-doped β-In2Se3 form were grown by the Bridgman method. This compound, the composition of which is In1.94Sb0.06Se3, appears to be closely connected with the tetradymite structure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature dc conductivity is 2 × 10−2 Ωcm−1, and it is an n-type semiconductor with a band gap of 1.34 eV.The phase diagram In{sub 2}Se{sub 3}-Sb{sub 2}Se{sub 3} was constructed from DTA and X-ray diffraction analysis data. No compound was observed in it, but two finite regions of In{sub 2}Se{sub 3}-based solid solutions were found: the first one, called {beta}{prime} (from 10 to 3.5 mol% Sb{sub 2}Se{sub 3}), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb{sub 2}Se{sub 3}) being the {beta}-In{sub 2}Se{sub 3} stabilized form. Crystals of the antimony-doped {beta}-In{sub 2}Se{sub 3} form were grown by the Bridgman method. This compound, the composition of which is In{sub 1.94}Sb{sub 0.06}Se{sub 3}, appears to be closely connected with the tetradymite structure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature dc conductivity is 2 {times} 10{sup {minus}2} {Omega}/cm, and it is an n-type semiconductor with a band gap of 1.34 eV.

Phase diagram equilibria in In{sub 2}Se{sub 3}-Sb{sub 2}Se{sub 3} crystal growth of the {beta}-In{sub 2}Se{sub 3} phase (In{sub 1.94}Sb{sub 0.06}Se{sub 3})

Abstract The phase diagram In2Se3–Sb2Se3 was constructed from DTA and X-ray diffraction analysis data. No compound was observed in it, but two finite regions of In2Se3-based solid solutions were found: the first one, called β′ (from 10 to 3.5 mol% Sb2Se3), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb2Se3) being the β-In2Se3 stabilized form. Crystals of the antimony-doped β-In2Se3 form were grown by the Bridgman method. This compound, the composition of which is In1.94Sb0.06Se3, appears to be closely connected with the tetradymite structure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature dc conductivity is 2 × 10−2 Ωcm−1, and it is an n-type semiconductor with a band gap of 1.34 eV.The phase diagram In{sub 2}Se{sub 3}-Sb{sub 2}Se{sub 3} was constructed from DTA and X-ray diffraction analysis data. No compound was observed in it, but two finite regions of In{sub 2}Se{sub 3}-based solid solutions were found: the first one, called {beta}{prime} (from 10 to 3.5 mol% Sb{sub 2}Se{sub 3}), of the tetradymite structure, and the second (from 3.5 to 0 mol% Sb{sub 2}Se{sub 3}) being the {beta}-In{sub 2}Se{sub 3} stabilized form. Crystals of the antimony-doped {beta}-In{sub 2}Se{sub 3} form were grown by the Bridgman method. This compound, the composition of which is In{sub 1.94}Sb{sub 0.06}Se{sub 3}, appears to be closely connected with the tetradymite structure. The refined unit-cell parameters of the hexagonal cell are a = 397(2) pm and c = 2827(2) pm. Its room temperature dc conductivity is 2 {times} 10{sup {minus}2} {Omega}/cm, and it is an n-type semiconductor with a band gap of 1.34 eV.

A thermodynamic study of gas transport in the growth of antimony telluride thin films

Abstract In order to determine the growing conditions of thin films of Sb 2 Te 3 in the hot wall epitaxy (HWE) technique, a thermodynamic model for the sublimation of the Sb 2 Te 3 phase was studied. The equilibrium constant was calculated, and the expressions for the fluxes and pressures of the components were determined. From these results, equations for the sticking coefficient and the deposition rate, expressed as functions of the source and substrate temperatures only, were formulated.