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In this study, stoichiometric lithium niobate (LiNbO3) single-crystal fibers were grown by the laser-heated pedestal growth (LHPG) method using different compositions with [Li2CO3]/[Nb2O5]=48.6:51.4, 50:50, 55:45 and 58:42 seeds. X-ray/CCD and ICP-AES were used to confirm the crystalline structure and the composition of the fibers, respectively. Electron spectroscopy for chemical analysis (ESCA) was used to analyze the [Li]/[Nb] ratio along the axis of the fibers. Based on these measurements, the growth mechanism that produces stoichiometric LiNbO3 fibers from stoichiometric feeding rods was investigated. The results show that the growth of stoichiometric LiNbO3 fibers using the LHPG method followed the equilibrium phase diagram concept.

Near equilibrium, phase transformations depend primarily on the thermodynamics of the system; the redistribution of components caused by the phase transformation are predictable from the appropriate phase diagram. However, far from equilibrium, when the transformation proceeds at such a rapid rate that there is little time for diffusion, the equilibrium phase diagram seems to be no longer relevant. It is generally agreed that the thermodynamic properties of the phases involved must still play an important role in the transformation. The nature of that role has not been understood. In this paper we report the results of computer simulations which have indicated the nature of that role. These are Monte Carlo simulations of the motion of an interface through a two component mixture without diffusion in either phase. In these simulations, we find that the interface hangs up on the atoms of the species which are rejected by the growing phase, making the interface compositions different from the bulk compositions. The interface compositions depend on the thermodynamic properties of the phases at the interface. But the interface compositions do not imply corresponding changes in the bulk phases after the interface has passed, as suggested by the phase diagram. This simple yet compelling picture provides the missing link between kinetics and thermodynamics in the rapid growth regime.

Closed form functions, describing the equilibrium phase diagram liquids and solidus lines of the Hg-Cd-Te system in the Te-rich corner are presented. Harman's experimental data of LPE epilayer composition and modified direct observation liquidus temperature are used for the numerical functions determination. The difference between LPE epilayer composition and thermodynamic equilibrium solidus composition is pointed out, and a LPE simulation procedure is used to deduce solidus line data from epilayer composition. This numerical description of the phase diagram can be satisfactorily used in simulation programs of epitaxial processes.

Linear growth rates and compositions of m-chloronitrobenzene-m-fluoronitrobenzine solid solution crystals were investigated experimentally. By extrapolating to zero growth rate, the equilibrium temperature and the equilibrium composition of the solid solution were determined for a given melt, and then the equilibrium phase diagram was constructed. The growth rates were found to vary with the square of the supercooling and the compositions were dependent on the growth rates. The growth rates and the compositions were quantitatively analyzed and were correlated with the supercoolings and the growth rates respectively. The growth rates of the pure and solid solution crystals, were shown to be comparative and this suggested a common similar growth mechanism.

Resume Mass spectrometry studies of Gd 2 O 3 -Ga 2 O 3 mixtures have resulted in partial determination of equilibrium phase diagram and Ga 2 O 3 activity variations with composition of mixtures. Lattice parameter measurements have specified width and limits of the garnet phase solid solution domain. The congruently melting composition was found to be equal to Gd 3.05 Ga 4.95 O 12 . The proposed phase diagram explains all experimental results reported up to now.

The effects of the composition and rate of solidification on mode (δ or γ) o austenitic stainless steels are studied on the bases of former experimental results and of a theoretical analysis of constrained dendrite growth. The position of the eutectic (laδ+γ) line in the Fe-Cr-Ni equilibrium phase diagram is ascertained by differental thermal analysis for 10.5

With a high temperature microcalorimeter the molar excess enthalpies of mixing for liquid gallium-indium-antimony alloys have been measured at 995 K. From these results and those already obtained for the limiting binary alloys we calculated the whole set of thermodynamic functions in this ternary system. The knowledge of the Gibbs free energies of mixing and of the thermodynamic functions of the GaSb-InSb quasi-binary system enabled one to compute the liquidus of the equilibrium phase diagram on the whole concentration range. The agreement between a few published experimental data and calculated points has been found satisfactory.

The molar mixing functions of some II–VI liquids (Zn-Se, Cd-Te, Hg-Te, Cd-Hg-Te) are obtained by fitting partial pressure data, liquidus lines (binary case) and liquidus surfaces of CdxHg1−xTe(s) alloys. Constraints, at the melting point of the zincblende, amongst all the data yield up to six independent parameters per binary, assuming Redlich-Kister polynomia forms for mixing functions in an associated solution model. The associated character is then found to decrease from Zn-Se to Hg-Te melts. Ternary interactions are taken into account in the Cd-Hg-Te liquid, whereas pseudobinary alloys appear nearly ideal.

A special technique of optical absorption using a microscope allows us to study the transmission at selected wave length in each point of the sample. The spatial resolution is about 100μm. Some local variations of the composition x minus than 10 -3 are measured for direct band gap materials. The solid-liquid equilibrium phase diagram allows us to correlate these variations to fluctuations of temperature and composition in the liquid at the growth interface. Some values as small as 0.1°C and 10 -5 , respectively, can be deduced. The method is a new, very sensitive tool for the knowledge of phenomena at the growth interface for multicompound semiconducting systems.

A method for the crystal growth of In 5 Bi 3 and In 2 Bi compounds, based on revised equilibrium phase diagram of the In-Bi system, is reported. Some transport properties of the obtained crystals are also presented.