B. Legendre

Phase diagram of the ternary system Ge-Sb-Te: II. The subternary Ge-GeTe-Sb2Te3-Sb

Abstract The phase diagram of the ternary subsystem Ge-GeTe-Sb 2 Te 3 -Sb was investigated using differential thermal analysis, differential scanning calorimetry, thermogravimetry powder X-ray diffraction and metallographic techniques. Five isoplethal sections were constructed. Seven transition reactions (U type) and a melting point minimum of the liquidus surface were characterized. Eight isothermal sections have been constructed in order to follow the reaction path for any composition of the subsystem.

Phase diagram of the ternary system GeSbTe. I. The subternary GeTeSb2Te3Te

Abstract The GeTeSb 2 Te 3 Te phase diagram was investigated using differential thermal analysis, differential scanning calorimetry, thermogravimetry, powder X-ray diffraction and metallographic techniques. Isopleths of four composition sections were constructed. Five transitory reactions (U type) were characterized with compositions in the range 8.5–15 at.% Ge and about 84.5 at.% Te and temperatures very close one of the other. There are also indications of a eutectoid reaction at about 45 at.% Ge and 52 at.% Te. Seven isothermal sections are presented.

Enthalpy of formation of Al–Fe–Si alloys (τ5, τ10, τ1, τ9)

Abstract In order to optimise the phase equilibrium of the ternary system Al–Fe–Si it is necessary to use thermodynamic data. In this paper we present the enthalpy of formation of ternary alloys at 298 K. These values were measured with a Tian-Calvet calorimeter (Setaram) by dissolution in an aluminium bath at 800°C (1073 K). After levitation melting, the alloys were annealed until they were monophasic, they were then checked by X-ray diffraction and the precise composition was determined by atomic absorption spectroscopy.

Experimental equilibrium phase diagram of the Ag–Bi–Sn system

Abstract The equilibrium phase diagram of Ag–Bi–Sn ternary system was studied by X-ray powder diffraction analysis, differential scanning calorimetry and differential thermal analysis. Three isopletic sections were studied: 10 at.% Bi, 40 at.% Ag and 70 at.% Bi. Three transitory invariant reactions were characterized: two ternary transitory peritectics and one ternary eutectic. Moreover, from all equilibrium temperatures we were able to propose a description of ternary liquidus surface in the whole composition range.

Thermodynamic investigation in In–Sb, Sb–Sn and In–Sb–Sn liquid systems

Abstract Using a molten salt method, EMF measurements have been obtained for In–Sb, Sb–Sn and In–Sb–Sn alloys. New DSC experiments on Sb–Sn system gave a confirmation of the proposed Sb–Sn equilibrium phase diagram. A thermodynamic description of the ternary liquid in fair agreement with the experimental results has been obtained from the geometrical Muggianu approach.

Thermodynamic evaluation of the Germanium — Tellurium system

Abstract In order to optimize the binary Ge-Te system available experimental data were critically compiled from the literature. The cubic high-temperature β-phase and the rhomboedric room-temperature α-phase were described by a two-sublattice model with one kind of defect (vacancies on germanium sites). The room-temperature orthorhombic γ-phase was treated as a stoichiometric compound, as there is a lack of information about its solubility. The liquid phase was modelled by the the associate model with one kind of associate, namely ‘GeTe’. A set of thermodynamic parameters was obtained and the calculated phase diagram is presented.

Importance of heat capacity determination in homogeneous nucleation: application to progesterone

Progesterone is known to exist under different crystallographic forms in the solid state. The thermodynamic stable form (I), melts at 129.2 ◦ C (402.35 K) under atmospheric pressure. After melting and cooling a metastable form (II) can be obtained which melts at 122 ◦ C (395.15 K). This uncommon behaviour can be explained with the theory of nucleation, only if heat capacity of the different forms are known.

Phase diagram of the ternary system GeSbSe

Abstract The ternary system GeSbSe was investigated by differential thermal analysis, differential scanning calorimetry, thermogravimetry, X-ray diffraction at fixed and varying temperatures and metallographic microscopy. The quasi-binary system Sb2Se3GeSe2, and various isoplethal and isothermal sections were determinated. In the quadrilateral GeGeSe2Sb2Se3Sb system there is a large liquid-liquid miscibility gap and a solid ternary solution. Seven reactions were observed corresponding to a monotectic, three peritectics, a eutectic, peritectoid and a eutectoid. The triangle GeSe2Sb2 Sc3Se is of the eutectic type.

Phase diagram of the Ag-Bi-Sb ternary system

Abstract The phase diagram of the Ag–Bi–Sb ternary system has been determined using X-ray powder diffraction analysis and differential scanning calorimetry. Three isopletic sections were studied: 10 at.% Bi and 70 at.% Ag and 10 at.% Ag. The results showed two ternary transitory peritectics. A schematic representation of the ternary equilibria is given.

Study of the ternary system germanium–antimony–tin: experimental phase diagram☆

Abstract The phase diagram of the ternary system Ge–Sb–Sn was established by X-ray powder diffraction and differential scanning calorimetry. No ternary compound was found. Two vertical sections were studied in order to follow the reaction path. Four ternary reactions were characterised: three transition peritectic (U-type) reactions and one eutectoid (E-type) reaction. Moreover, from all equilibrium temperatures, a description of liquidus surface in the whole composition range is proposed.