The phase diagram of the BaO(BaCO3)-CaO-CuO system, especially in the barium-rich region at 900°C in air, was studied. Two new different oxycarbonates were observed: Ba8Ca16/15Cu64/15O11.20(CO 3)2.66 and a solid-solution series with a chemical composition of Ba2Cax+yCu1+(x/2)-yO2+δCO 3)1-z (where 0 ≤ x ≤ 2/39 and 0 ≤ y ≤ 16x/5). The oxycarbonate solid solution was formed in a region of the compositional triangle Ba:Ca:Cu (in moles) = (2:0:1)-(39:l:20)-(65:7:28). The solid-solution structure had P4/mmm symmetry, with lattice parameters a ≈ ap and c ≈ 2ap, where ap represents the perovskite cell. The Ba8Ca16/15Cu64/15O11.20(CO 3)2.66 compound, which had Pm3m symmetry with a lattice parameter a = 0.8116(2) nm, had no chemical-solubility range.
|Number of pages||4|
|Journal||Journal of the American Ceramic Society|
|Publication status||Published - 1999|
ASJC Scopus subject areas
- Ceramics and Composites
- Materials Chemistry