Size effects in the melting and crystallization temperatures of copper chloride nanocrystals in glass

Abstract

The size dependence of the crystallization temperature T c and melting temperature T m of copper chloride nanocrystals in glasses is studied in the size range R a from 1 to 30 nm. Jumps are found in the temperature dependence of T c at R a =13 nm and R a =1.8 nm, a jump is found in the temperature dependence of T m at R a =2.2 nm, and the supercooling of the melt is found to vanish in the case of crystallization at R a ⩽1.4 nm. It is conjectured that the jump in T c with large R a occurs for a nano-crystal radius equal to that of a crystalline nucleus in the melt, and the jumps in T c and T m for smaller values of R a are due to a change in the shape (faceting) of the nanocrystals.