TY  - JOUR
AU  - Lozano-Gorrín, A.D.
AU  - Greedan, J.E.
AU  - Núñez, P.
AU  - González-Silgo, C.
AU  - Botton, G.A.
AU  - Radtke, G.
T1  - Structural characterization, magnetic behavior and high-resolution EELS study of new perovskites Sr2Ru2-xCoxO6-δ (0.5≤x≤1.5)
LA  - eng
PY  - 2007
SP  - 1209
EP  - 1217
T2  - Journal of Solid State Chemistry
SN  - 0022-4596
VL  - 180
IS  - 4
AB  - New oxides of general formula Sr2Ru2-xCoxO6-δ (0.5≤x≤1.5) have been synthesized as polycrystalline materials and characterized structurally by X-ray diffraction. For 0.5≤x<0.67 the orthorhombic, Pnma, perovskite structure of the end member, SrRuO3, is found. At x=0.67 a phase separation into an Ru-rich Pnma phase and a Co-rich I2/c phase occurs. The I2/c form is also found for x=1.0 but another orthorhombic phase, Imma, obtains for x=1.33 and 1.5. Reductive weight losses indicate negligible oxygen non-stoichiometry, i.e., δ∼0, for all compositions even those rich in Co. High-resolution electron energy loss spectroscopy (EELS) indicates that cobalt is high-spin Co3+ or high-spin Co4+ for all x. Appropriate combinations of Ru4+, Ru5+, HS Co3+ and HS Co4+ are proposed for each x which are consistent with the observed Ru(Co)-O distances. Significant amounts of Co4+ must be present for large x values to explain the short observed distances. Broad maxima in the d.c. susceptibilities are found between 78 and 97 K with increasing x, along with zero-field-cooled (ZFC) and field-cooled (FC) divergences suggesting glassy magnetic freezing. A feature near 155 K for all samples indicates a residual amount of ferromagnetic SrRuO3 not detected by X-ray diffraction. © 2007 Elsevier Inc. All rights reserved.
DO  - 10.1016/J.JSSC.2007.01.019
UR  - https://portalciencia.ull.es/documentos/5e3c34a729995246bbf5cd5e
DP  - Dialnet - Portal de la Investigación
ER  -