Experiments have been performed on the distribution coefficients of a number of solute elements in germanium crystals grown from the melt. The variation of distribution coefficient with conditions of crystallization is examined in the light of the theory of Part I. The incorporation of solute elements into the crystal is shown to depend critically upon the transport processes occurring in the melt.

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The diffusivity and solubility of Cu in Ge have been investigated as a function of temperature in the temperature range 700°-900°C, both by resistivity and radio-activity methods. The average diffusivity is 2.8±0.3X10~5 cm 2 /sec in this temperature interval. The solubility shows a maximum of 4.0X10 16 atoms of copper cm -3 at about 875°C. The precision is not sufficient to determine an activation energy for diffusion. However, calculations based upon a theory of Wert and Zener, indicate an activation energy of about 4000 cal. The "thermal conversion" effect in Ge is explained by a temperature-dependent solution and precipitation of Cu. It is suggested that the acceptor and diffusional properties of Cu in Ge can be accounted for by decreased electron affinity of Cu at higher temperatures.

The solubilities of antimony in solid germanium and copper in solid silicon were found to increase with temperature as had been observed previously for copper in germanium, i.e., these binary alloys possess retrograde solidus curves. It is shown theoretically that this phenomenon can occur in solutions with simple properties, for example, in an ideal liquid solution in equilibrium with a dilute solid solution for which the differential heat of solution of the solute is independent of composition and temperature and the differential entropy of solution is ideal. The logarithms of the distribution coefficients of antimony and copper in germanium, and copper in silicon are linear functions of the reciprocal of the absolute temperature. Extrapolation to the melting point of germanium gives the distribution coefficients of antimony and copper at this temperature. A similar extrapolation to the melting point of silicon is made for copper in silicon. Measurements of the distribution coefficients near the melting points were made during the growth of single crystals and found to be in agreement with the extrapolated distribution coefficients. The complete solidus curves between the melting points of germanium or silicon and the respective eutectic tempertures have been constructed for antimony and copper in germanium and for copper in silicon.

Electrical instabilities in SiO2 films under high fields at elevated temperatures have been widely attributed to mobile ionic impurities, with sodium suspected as the most important ion. Phosphate glass treatments on SiO2 are known to have a stabilizing effect. This paper reports neutron activation experiments to determine sodium contamination on and in steam‐grown SiO2 films and also diffusion and drift experiments with tracer sodium. Phosphate glass‐treated SiO2 films were included in the samples. SiO2 films grown and handled under various conditions had sodium densities of 7×1011 normalto 3×1014 normalatoms/cm2 , which could be easily removed or exchanged by washing and light etching. Densities remaining inside the 6000Aå films after washing and light etching were ⋜4×1011–4×1012/cm2 .Tracer diffusions into SiO2 at 600°C produced profiles which were high near the surface and lower through the interior of the film, similar to those observed by neutron activation for unintentional sodium contamination. Phosphate glass layers on SiO2 absorbed and stopped the sodium under similar conditions. With an applied field at elevated temperature (+4v, 1 min, 400°C) tracer sodium drifted through an SiO2 film under gold dot electrodes, piled up at the normalSi‐SiO2 interface, and carried a substantial part of the charge transported. There was no detectable diffusion in uncharged areas. A layer of phosphate glass applied over an SiO2 film absorbed sodium and prevented it from drifting into the SiO2 film under the gold dots.