Amorphization of silicon during mechanical treatment of its powders: 2. Heats of recrystallization

Exothermic effects arising during silicon powder heating after their mechanical treatment were measured by synchronous TG-DSC thermal analysis method. Silicon samples possessed semicrystalline structure. As temperature varied from room temperature to 1200 degreesC at a rate of 10 and 50 deg/min, the heat was released in the range 550-800 degreesC. The crystallization of amorphous phase was also observed in the same temperature range using the X-ray diffraction. As the amount of energy consumed during the mechanical treatment of powders increased, the value of the heat effect rose synchronously with the degree of amorphization. In this case, the ratio of the released heat to the content of X-ray amorphous phase was constant and equal to 6 +/- 2 kJ/mol.