Structural, magnetic, electronic, and dilatation properties of the ordered solid solutions Ln(0.2)Sr(0.8)CoO(3-delta) (Ln = Sm, Gd, Dy) with the same oxygen nonstoichiometry index delta

摘要

Single-phase samples of the layered perovskite-like cobalt oxides Ln(0.2)Sr(0.8)CoO(3-delta) (Ln = Sm, Gd, Dy) with the same oxygen nonstoichiometry index delta = 0.37 +/- 0.01 were synthesized. All samples are characterized by a tetragonal unit cell with the space group I4/mmm. The structural, magnetic, electric transport and dilatation properties of the obtained samples are investigated. The studied samples are characterized by two anomalies in magnetic properties, a high-temperature maximum near T-m = 350 K with magnetic field hysteresis below T-m, and a diffuse peak in the intermediate temperature range, which shifts with ionic radius decrease of the rare-earth element to higher temperatures. The high-temperature maxima of the magnetic susceptibility correlate with anomalies in thermal expansion, heat capacity and the features in the temperature dependences of the electrical resistivity, pointing to a strong relationship between the structural, magnetic and electronic degrees of freedom. The given comparative analysis of the experimental data of various substituting rare-earth elements with the same oxygen nonstoichiometry has been carried out for the first time. (c) 2020 Elsevier B.V. All rights reserved.