Coexistence of ferromagnetic and spin glass-like magnetic order in Bi10Co16O38 – Bi25FeO40 powder composite

Abstract

Abstract In this article, structural and magnetic characteristics of Bi 10 Co 16 O 38 – Bi 25 FeO 40 (BCFO) sillenite composite powder prepared via hydrothermal route were explicated. Structural and microstructural details were studied using XRD and FE-SEM techniques. The magnetic ordering was probed with both static magnetization (M vs. T, M vs. H) and dynamic AC susceptibility measurements. The detailed magnetic analysis confirms the coexistence of ferromagnetic, spin-glass magnetic order below the Curie transition temperature of 227\u202fK with a spin freezing temperature at 161\u202fK. Critical slowing down parameter zv of 1.36 indicates mean field dependent phenomena for the observed spin glass transition temperature. Furthermore, the ferromagnetic contribution in the composite is ascribed to the low-spin state of Co 2+ ion.