Growth striations in Fe-3wt%Si single crystals grown by floating zone melting at various growth rates

Abstract

Growth striations have been studied in Fe-3wt%Si single crystals grown at various growth rates using floating zone melting with inductive heating. Well developed striations have been observed only in crystals grown at rates of 64 and 120 mm h-1. In crystals grown at a rate of 21 mm h-1 only weak indistinct striations have been revealed. No striations have been observed in crystals grown at a rate of 7 mm h-1. The striation structure has not been influenced by rotation of melted rod. It is suggested that unsteady surface tension-driven flow could be the dominant source of striations at floating zone melting. Some experiments indicate that the formation of striation is significantly suppressed at lower growth rates. Furthermore, solid-state diffusion of silicon could modify the striation structure during crystal growth, especially at lower growth rates.