The most significant structural feature of the A-site ordered manganese perovskites, RBaMn2O6, is that the MnO2 square sublattice is sandwiched by two types of rock-salt layers, RO and BaO, with much different sizes and consequently the MnO6 octahedron itself is distorted in a noncetrosymmetric manner. The structures and electromagnetic properties of RBaMn2O6 (R = La, Pr and Nd) have been investigated. They have tetragonal structures with no tilt of MnO6 octahedra and show ferromagnetic metal transitions. The ground state is a coexistence of ferromagnetic metal and antiferromagnetic charge-orbital ordered phases for LaBaMn2O6 and A-type antiferromagnetic metal for PrBaMn2O6 and NdBaMn2O6. These ground state behaviors are explained by the effect of Mn-O distance on the bandwidth and the layer structure with the RO-MnO2-BaO-MnO 2 stacking along the c-axis.
ASJC Scopus subject areas
- Physics and Astronomy(all)