Transmission electron microscopy studies of La2O3-doped alpha-SiAlON ceramics

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. In this study, the possibility of being able to introduce the relatively large La3+ cation into the alpha-SiAlON crystal structure has been investigated. For this, alpha-SiAlONs doped with (i) La2O3 and CaO and (ii) La2O3 and Yb2O3 were produced. Energy dispersive X-ray spectrometry results confirm that lanthanum can indeed be incorporated into the alpha-SiAlON structure if other smaller cations are also present.