Floating-zone growth and characterization of Fe2SiO4 single crystals

High quality single crystals of fayalite, Fe2SiO4, with well-developed morphology were successfully grown by the floating-zone method under a controlled atmosphere. Crystals, similar to 7-10 mm in diameter and similar to 40-60 mm in length, were grown along the three major crystallographic axes. All crystals had well-developed facets or flat surfaces and were free of inclusions at the resolution of routine electron microscopy. The Fe/Si atomic ratio determined by the ICP-AES technique was 1.992. The most numerous crystal defects observed were bubbles; the dislocation densities as revealed by etching were approximately 5 x 10(4)/cm(2).