Structural, Magnetic, and Thermodynamic Properties of Ordered and Disordered Cobaltite Gd0.1Sr0.9CoO3-

Dudnikov, V. A.; Kazak, N. V.; Orlov, Yu. S.; Vereshchagin, S. N.; Gavrilkin, S. Yu.; Tsvetkov, A. Yu.; Gorev, M. V.; Veligzhanin, A. A.; Trigub, A. L.; Troyanchuk, I. O.; Ovchinnikov, S. G. Source: JOURNAL OF EXPERIMENTAL AND THEORETICAL PHYSICS, 128 (4):630-640; 10.1134/S1063776119020171 APR 2019

The effect of cationic and anionic orderings on the crystal structure and magnetic properties of substituted rare-earth cobaltites Gd0.1Sr0.9CoO3 – δ was studied using X-ray diffraction, measurement of XANES spectra, and magnetic and thermodynamic characteristics. The effects of ordering cause a decrease in symmetry to tetragonal and a distortion of the coordination octahedra of CoO6. Anomalous magnetic and thermodynamic quantities are observed at 260 and 360 K, respectively, for disordered and ordered samples. The XANES spectra measured at the CoK edge did not reveal a noticeable shift in the absorption edge compared with the spectrum of original GdCoO3. This suggests that the charge compensation process is associated not only with a change in the electronic state of cobalt ions, but also with the emergence of holes in the 2p states of oxygen.