Incorporation of the transition metals (Cr and Fe) into β-SiAlON crystal structure

Outstanding properties for SiAlON ceramics can be obtained by tailoring the microstructure through α-SiAlON and β-SiAlON phase content as well as a type of secondary phases. It is so far well known that while some of the elements could be accommodated in α-SiAlON structure, β-SiAlON does not easily accommodate different elements in its structure. In this work, SiAlON ceramics were produced by using β-Si3N4 starting powder containing small amount of iron and chromium and the possible incorporation of iron and chromium into β-SiAlON structure was investigated by using analytical transmission electron microscopy (TEM) techniques. As a result of analytical TEM analysis, it is found that transition metals (Cr and Fe) can enter into the β-SiAlON crystal structure.