Similar Growth Mechanism Research Articles

Interface Characterization of PbTe/BaSi/Si Heterostructures Grown Using MBE

ABSTRACTA new substrate material consisting of a buffer layer of a Ba-Si compound was developed by making use of the chemical reaction between BaF2 and Si. This substrate is very promising for the integration of IV-VI semiconductor materials with silicon. PbTe films of excellent quality, as determined by X-ray and Reflected High Energy Electron Diffraction spectra, have been deposited over (111)- and (100)-oriented silicon wafers of 3 inch diameter. These PbTe films are (100)-oriented irrespective of the Si orientation. X-ray photoelectron spectroscopy studies reveal very interesting chemistry at the interface between Ba-Si and Te. They suggest that BaTe may form between PbTe and Ba-Si at their interface. This interfacial region, which is of the order of only a few molecular layers, appears to be critical in the success of the deposition. Thermal cycling showed that the PbTe/BaSi/Si system is mechanically very stable. The possibility of a similar growth mechanism for the deposition of II-VI semiconductors such as CdTe is considered.

Growth rates and compositions of organic solid solution crystals from binary melts — Experimental study

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.

Speculations on a New Mechanism of Crystal Growth from Aqueous Solutions

AbstractThe activity of lead ions to form heterogeneous nuclei in supersaturated KCl solutions was shown (in previous publications) to account quantitatively for the effect of these ions on the limit of stability of the supersaturated solutions, the rate of crystallization, and the co‐precipitation of the lead ions with the crystallizing salt. Hence the process of crystal growth is described as the deposition of subcolloidal sized nuclei on the crystal seed. Many otherwise perplexing phenomena recorded in the literature, and observed in studies of various aspects related to the crystallization of KCl and NaCl, prove to be a direct consequence of this mechanism of crystallization. Other examples indicate that heteronucleation and a similar growth mechanism may be prevalent in the crystallization of several salts from their aqueous solutions. Some implications and possible applications of the proposed growth mechanism are also discussed.