Influence of annealing time on the magnetic properties of La0.8Sr0.2CoO3 compound

Abstract For the La 1− x Sr x CoO 3 compounds with x ⩽0.3, the formation of homogenous samples appear to depend strictly on the preparation conditions that cause the electronic and magnetic data reported scatter strongly. In the present contribution, the results of systematic investigation of the influence of annealing time ( t a ) on various magnetic parameters are reported for the x =0.2 substance, i.e. near the percolation threshold between spin-glass and cluster-glass phases. High Sr-concentration phases are initially formed at short t a but gradually transformed to lower Sr-concentration ones with longer t a . This transformation process apparently finishes at t a ≈200 h and homogenous samples with the purely expected stoichiometric phase can be obtained with longer t a . The results from transport measurements are also mentioned in comparison to the magnetic data.