Crystallization Behavior of Amorphous Si3N4 and Particle Size Control of the Crystallized α-Si3N4.

Amorphous silicon nitride powder prepared by low-temperature vapor-phase reaction was heat treated at various temperatures for different periods of time to examine the crystallization behavior. The effects of the heat-treatment temperature and duration on the degree of crystallization were investigated along with the effect of the heat-up rate on the particle size, and its distribution, of the crystallized α-phase silicon nitride powder. A phase transition from amorphous to α-phase occurred at a temperature above 1400 degrees C.

Bulk characterization methods for non-centrosymmetric materials: second-harmonic generation, piezoelectricity, pyroelectricity, and ferroelectricity.

Characterization methods for bulk non-centrosymmetric compounds are described. These methods include second-harmonic generation, piezoelectricity, pyroelectricity, and ferroelectricity. In this tutorial review with each phenomenon, details are given of the measurement techniques along with a brief history and background.