TRANSMISSION ELECTRON-MICROSCOPY STUDY OF BALL-MILLED GA-SB POWDER MIXTURE

Powders of mechanically ground (MG) Ga + 88 at% Sb were investigated b y X-ray diffraction (XRD), scanning and transmission electron microsco py (SEM, TEM), high resolution electron microscopy (HREM), selected ar ea diffraction (SAD) and energy dispersive X-ray analyses (EDS). In ba ll milling we obtained two nonequilibrium phases stable at room temper ature, i.e. amorphous antimony oxide and high-temperature antimony (HT ) oxide Sb2O3. The formation of amorphous oxide phase in grain boundar ies and development of HT Sb2O3 in its lamellar form from the amorphou s region of the sample milled for 16 h was observed by HREM and contro lled also with qualitative EDS. The model of appearance of HT Sb2O3 fr om the amorphous region of the sample is proposed from structural anal yses carried out by HREM and SAD. For different milling rates the obse rved microstructure showed a layered structure and nanocrystalline gra in sizes.