Structure, oxygen non-stoichiometry, and phase transitions in Ca1–хPrхMnO3–δ

Resumo

Manganites Ca_1–хPr_хMnO_3–δ, where 0 ≤ х ≤ 0.15 were studied. The compounds have orthorhombic structure (space group Pnma) at ambient temperature, which consecutively transforms on heating in air into phases with tetragonal I4/mcm and cubic 000000 structure. Increase in praseodymium concentration leads to higher phase transition temperatures, lower heat of structural transformations, more narrow homogeneity range of oxygen, and a wider temperature interval of tetragonal I4/mcm phase existence.