Abstract
The solidus boundary in the GaP-InP system was determined by a technique which uses the electron microprobe to analyze the solid phase of compositions equilibrated in the solid-liquid phase field. The boundary shows the substantial positive deviation from ideal behavior found in a number of other analogous III-V systems. Vegard's law for the relation between lattice parameter and composition holds for this system. © 1970, The Electrochemical Society, Inc. All rights reserved.