Magnetic behaviour near the magnetic-phase transition in La1-xSrxCoO3 (0.20 <= x <= 0.30) perovskites

Measurements of the temperature dependence of the magnetization (and parame ters Like coercivity and susceptibility) of La1-xSrxCoO3 (0.20 less than or equal to x less than or equal to 0.30) perovskites are presented, Particul ar attention is given to the interval of temperatures containing the ferro- paramagnetic phase transition. Curie temperature values lower than those re ported previously and critical exponents are given. Additionally, the coerc ivity as well as the parameters of the law of approach to magnetic saturati on are experimentally determined. Anomalies in Curie temperature, coercivit y and law of approach to saturation are introduced confirming a non-convent ional transition from ferromagnetic to paramagnetic states. (C) 1999 Elsevi er Science B.V. All rights reserved.