Mechanical Grinding and Reforming Process of the Bi-2201 Phase

Abstract

Mechanical grinding and the reformation from ground powder of the Bi-2201 phase were examined by XRD, TEM and DTA. The "2201" phase changed easily into amorphous powder and ultra-fine crystals by mechanical grinding. When heated above 800°C, the ground powder reacted to reform the original "2201" phase. The fine "2201" crystals smaller than a critical size remaining in the ground powder were decomposed into Bi₂CuO₄ and SrCO₃ by heating around 500°C in air, while even at room temperature in the air the XRD peaks from these ultra-fine crystals tend to disappear and SrCO₃ formed on grinding.