Optical, mechanical and water drop impact characteristics of polycrystalline GaP

Abstract

A polycrystalline form of GaP has been synthesized and its optical and mechanical properties determined. The optical transmission is found to be intrinsic at long wavelengths in the infrared, being limited only by Fresnel reflection and multiphonon absorptions, beginning at approximately 1100 cm−1. The optical cut-off at short wavelengths is in agreement with earlier measurements on single crystal material. The fracture toughness of the polycrystailine material is found to be greater than that previously reported for single-crystal material. The single impact water drop damage velocity threshold (2 mm drop diameter) was estimated to be 250–280 ms−1, which is consistent with the measured polycrystalline fracture toughness.