Magnetocaloric effect of LaFe _11.35 Co _0.6 Si _1.05 alloy

Abstract

Abstract The aim of the present paper was to study the large magnetocaloric effect observed in LaFe 11.35 Co 0.6 Si 1.05 alloy. X‐ray diffraction (XRD) result reveals a coexistence of two crystalline phases: a dominant La(Fe,Si) 13 ‐type and a minor α‐Fe(Co,Si). It is confirmed by the Mössbauer spectroscopy and microstructural observations accompanied by an energy‐dispersive spectroscopy (EDS) analysis. The value of the magnetic entropy changes (| S M |) in the vicinity of the Curie temperature ( T C = 268 K) was calculated using thermomagnetic Maxwell relation, and it equals to 21.4 J·kg −1 ·K −1 under the change in an external magnetic field of μ 0 Δ H = 3T. The investigation of magnetic phase transition was carried out using the Landau theory, an analysis of the field dependences of the magnetic entropy change and universal scaling curve, revealing the second order of phase transition in the studied material.