Neutron diffraction studies of the structure of substituted complex cobalt oxides |
| |
Authors: | V V Sikolenko V V Efimov S Schorr C Ritter I O Troyanchuk |
| |
Institution: | 1. Joint Institute for Nuclear Research, ul. Joliot-Curie 6, Dubna, Moscow oblast, 141980, Russia 2. Karlsruhe Institute of Technology, Kaiserstra?e 12, Karlsruhe, 76131, Germany 3. Helmholtz Center Berlin, Hahn-Meitner-Platz 1, Berlin, 14109, Germany 4. Institute Laue Langevin, 6 Rue Jules Horowitz, Grenoble, 38000, France 5. Scientific-Practical Materials Research Centre, National Academy of Sciences of Belarus, ul. P. Brovki 19, Minsk, 220072, Belarus
|
| |
Abstract: | The effect of substitution of manganese and niobium for cobalt on the magnetic and crystal structure of doped cobaltites has been studied by the neutron diffraction method. The Pr0.5Sr0.5Co1 ? x Mn x O3 samples undergo, with increasing x, a series of transitions of the crystal structure from the monoclinic I2/a to orthorhombic Immm phase, and then, to the high-temperature tetragonal I4/mcm phase and low-temperature orthorhombic Fmmm phase. Undoped Pr0.5Sr0.5CoO3 is a ferromagnet, but the magnetic ordering is destroyed with increasing x. At high degrees of substitution of manganese, the A-type antiferromagnetic ordering is observed. Substitution of niobium for cobalt in La1 ? x Sr x CoO3 compositions leads to changes in the Co-O bond length and the unit cell volume, which is accompanied by a decrease in the ferromagnetic moment. The Co → Nb substitution prevents the formation of Co4+ and leads to the stabilization of Co3+ in a high-spin state. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|