Weak ferromagnetism and superparamagnetic clusters coexistence in YFe1−xCoxO3 (0 ≤ x ≤ 1) perovskites

POMIRO, FERNANDO; GIL, DIEGO M.; NASSIF, VIVIAN; PAESANO, ANDREA; GÓMEZ, MARÍA I.; GUIMPEL, JULIO; SÁNCHEZ, RODOLFO D.; CARBONIO, RAÚL E.

MATERIALS RESEARCH BULLETIN

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2017 vol. 94 p. 472 - 472

0025-5408

Fe1-xCoxO3 (x = 0, 0.3, 0.5, 0.7 and 1) perovskite solid solutions were synthesized by thermal decomposition of the cyano-metal complexes Y[Fe1-xCox(CN)6]·4H2O. All perovskites belong to the orthorhombic Pnma space group. Mössbauer spectra at room temperature show that samples with low Co3+ content are magnetically ordered, while samples with high Co3+ content are paramagnetic. A clear decrease of the magnetic order temperature was observed by magnetization vs. temperature experiments. At high temperatures, YFe0.3Co0.7O3 is paramagnetic and a non common increase of magnetization is observed. The later can be related to the thermal excitation of Co3+ in low spin (LS) configuration to intermediate (IS) or high spin (HS) configuration. Along the different compositions of YFe1-xCoxO3 solid solutions there is a competition between weak ferromagnetism (WFM) and superparamagnetic (SPM) clusters. WFM due to Fe3+ cations prevail in rich Fe3+ samples (x = 0 and 0