Synthesis and crystal structure of (Sr1-xCax)2FeMnOy (x=0-1.0)

The compounds were synthesised in air at 1150-1200 C and their crystal structures and electrical properties investigated. Perovskite- type and brownmillerite-type compounds were formed in the compositional range x = 00.7 and x = 0.8-1.0, respectively. Ca2FeMnOy (x = 1.0) was the brownmilleritetype compound with lattice parameters a = 0.5338 nm, b = 1.4834 nm and c = 0.5515 nm. The angle of Fe-O-Mn was 151 degrees, calculated from there fined structure data of Ca2FeMnOy. The FeO4 tetrahedra and the MnO6 octahedra were alternately arranged zigzag along the b-axis. All samples exhibited p-type semiconducting behaviour. 7 refs.