Growth and Properties of Lanthanum Oxysulfide Crystals

Abstract

To better determine the optical properties of the rare‐earth oxysulfide phosphors and to lay the foundation for their application in single‐crystal form as scintillators and lasers we have grown, for the first time, single crystals of these materials. A description of present growth techniques will be presented. Materials problems and our progress toward their solutions will be discussed. Single‐crystal properties, such as optical transmission range, hardness, indices of refraction, thermal expansion coefficient, and thermal conductivity will also be reported. Work to date has emphasized lanthanum oxysulfide and, to a lesser extent, yttrium and gadolinium oxysulfide.