Floating-zone growth and characterization of single crystals of cobalt orthosilicate, Co2SiO4

Good quality single crystals of high purity cobalt silicate, Co2SiO4, were successfully grown by the floating-zone method in air at atmospheric pressure along the three principle orientations. The grown crystals were 30–60 mm in length and 6–10 mm in diameter. Well developed facets were found on all crystals grown. Impurity levels and the degree of a desired excess of silicon in grown crystals were determined by using the ICP-AES technique. In addition, the presence of a small amount of inclusions in the matrix of grown crystals due to a small excess of silica was confirmed by TEM. Dislocation densities were determined upon etching; the observed densities were on the order of 105–106 cm−2.