BAMN1-XFEXO3-DELTA, AN OXYGEN-DEFICIENT 6H' OXIDE - ELECTRON-MICROSCOPY, POWDER NEUTRON-DIFFRACTION, AND MOSSBAUER STUDY

A rather rare six-layer form of 'hexagonal perovskite' 6H prime , was isolated for BaMn//1// minus //xFe//xO//3// minus // delta (0 less than equivalent to x less than equivalent to 0. 3). X-ray powder diffraction and HREM studies have shown that the stacking sequence of the BaO//3 layers is hhhchc. The distribution of oxygen vacancies and octahedral cations were determined by powder neutron diffraction for x equals 0. 233. The coordination of iron was determined by Mossbauer spectroscopy.