Preparation and crystal imperfections of yttrium–iron garnet single crystals grown in flux melts by slowly cooling and gradient transport I. Striations

Abstract

Striations nearly parallel to the growth faces {110} and {211} were revealed by chemically etching, X-ray topography, and infrared transmission light microscopy in YIG single crystals grown in flux melts by slowly cooling and gradient transport. These striations are classified with regard to their amplitudes and periods. They result from an imperfect temperature controller and from irregular convection within the melt. Striations with a period of 2.5 to 5 μm are probably caused by the growth process itself. Microprobe measurements show a connection between the lead incorporation, the striations, and the growth conditions. The induced striation method allows the experimental determination of the nucleation temperature of each crystal in a run and the determination of the linear growth rate. Furthermore this method enables assertions about changes of the habitus during the growth process.