Formation of Nanosize Griffiths-like Clusters in Solid Solution of Ferromagnetic Manganite and Cobaltite

Abstract

We report the existence of a Griffiths-like phase over a wide range of x due to the formation of nanosize ferromagnetic clusters in La_0.6Sr_0.4Mn_1–xCoxO₃, the solid solution of ferromagnetic La_0.6Sr_0.4MnO₃ and La_0.6Sr_0.4CoO₃, from the magnetization measurements. In the studied compound, this phase arises due to the quenching of randomly distributed Co–O–Mn antiferromagnetic bonds in the ferromagnetic background. In contrary to the divalent alkaline-earth-doped manganites, the Griffiths-like phase in La_0.6Sr_0.4Mn_1–xCoxO₃ can exist entirely in the metallic state above TC (for x < 0.10). Based on the present study, a magnetoelectronic phase diagram is drawn.