Abstract
Crystallite size and lattice strain of commercial silicon nitride powders were calculated by Hall's equation from the powder X-ray diffraction patterns. α-percent in the crystal phase of silicon nitride powders was determined by using a calibration curve. Silicon nitride powder obtained from the nitridation of metallic silicon powders have a tendency to show little lattice strain and large crystallite size. The powder produced from silica showed large lattice strain. The powder synthesized from ammonolysis of SiCl4 and vapor phase reaction showed little crystallite size and a large littice strain.
