2015 年 123 巻 1441 号 p. 845-852
The solid state chemistry of mixed-metal oxides containing rare earths (4f elements) and 4d or 5d transition elements has attracted a great deal of interest, because these materials adopt a diverse range of structures and show a wide range of electronic properties due to 4f and 4d (or 5d) electrons. We have focused our attention on the structural chemistry and magnetic properties of perovskite-type oxides with the general formula AnLnMn−1O3n (A = Ca, Sr, Ba; Ln = rare earths; M = Ru, Ir; n = 1–4). Their structures are controlled by changing the ratio of the Ln and M ions, and peculiar magnetic properties and magnetic structures have been investigated by magnetic susceptibility, specific heat and neutron diffraction measurements.