Magnetocaloric effect and critical behavior in ternary equiatomic magnesium compounds REPtMg (RE = Tb, Dy and Ho).

The magnetocaloric effect (MCE) and critical behavior in the RE PtMg (RE = Tb, Dy and Ho) intermetallic compounds around Curie temperatures T C were investigated by magnetization measurements. All the RE PtMg compounds exhibit pronounced MCE performance with the maximum magnetic entropy change (− Δ S M max ) values up to 5.1, 7.2, 10.2 J/kg K under the magnetic field change (Δ H) of 0–5 T around T C of 58, 29, and 20 K for RE = Tb, Dy and Ho, respectively. The reasonable and accurate critical exponents for the present RE PtMg series compounds for RE = Tb, Dy and Ho obtained by the Δ H dependence of Δ S M method are evaluated to be β = 0.4691, 0.4681, 0.4141, γ = 1.0412, 1.0482, 1.1067 and δ = 3.2196, 3.2393, 3.6728 around T C , which are verified by the Widom scaling law and scaling equations, respectively. • The magnetocaloric property in RE PtMg (RE = Tb, Dy and Ho) was studied. • A considerable reversible MCE was observed for all compounds. • The critical behavior in RE PtMg (RE = Tb, Dy and Ho) were studied. • The obtained critical exponents obey the Mean-field model. [ABSTRACT FROM AUTHOR]