Structures and electromagnetic properties of the A-site disordered Ba-based manganites; R_(0.5)Ba_(0.5)MnO_3 (R = Y and rare earth elements)

摘要

The discovery of novel structural and physical properties in the A-site ordered manganite RbaMn_2O_6 (R = Y and rare earth elements) has demanded new comprehension about perovskite manganese oxides. In the present study, the A-site disordered form, R_(0.5)Ba_(0.5)MnO_3, was successfully synthesized and investigated in the structure and electromagnetic properties. R_(0.5)Ba_(0.5)MnO_3 has a primitive cubic perovskite cell. The magnetic glassy states are unexpectedly dominant as the ground state of R_(0.5)Ba_(0.5)MnO_3 in contrast to the ordinary disordered manganite R(0.5)A_(0.5)MnO_3 (A = Sr and Ca). A peculiar behavior that is the steplike ultrasharp magnetization and resistivity change has been observed in R_(0.5)Ba_(0.5)MnO_3.