Formation of alpha-SiAlON ceramics containing scandium

Abstract

alpha-SiAlON is able to accommodate cations into its crystal structure if the cations are sufficiently small in size, thus helping to reduce the volume of the remnant grain boundary phase after processing. Lutetium with an ionic radius of 0.85 Angstrom was the smallest 3+ cation which can be incorporated into alpha-SiAlON structure and the Sc+3 cation, with an ionic radius of 0.73 Angstrom was accepted too small to form an alpha-SiAlON. In the present work, the possibility of having the Sc+3 as a dopant cation into alpha-SiAlON structure has been investigated. XRD and energy dispersive X-ray measurements (EDX) analyses have proven that Sc+3 cations can be accommodated into alpha-SiAlON structure.