Structural, magnetic properties and magneto-caloric performances in the antiferromagnetic RECoSi2 (RE = Er and Tm) compounds

Abstract

The ternary rare earth RECoSi2 (RE = Er and Tm) intermetallic compounds were synthesized by means of arc-melting technique and their crystal structure, magnetism and magneto-caloric effect (MCE) were studied systematically. Both ErCoSi2 and TmCoSi2 crystallize in a CeNiSi2-type structure (Cmcm space group) confirmed by FULLPROF Rietveld refinement. Magnetization data indicates the antiferromagnetic (AFM) ground state for both RECoSi2 compounds, and a magnetic field-induced ferromagnetic (FM) transition occurs below the Neel temperature TN ∼6.9 K for ErCoSi2 and ∼5.4 K for TmCoSi2. Considerable reversible MCE in ErCoSi2 and TmCoSi2 was observed. The MCE performances of RECoSi2 are evaluated by -ΔSMmax (maximal magnetic entropy change), TEC(3) (temperature averaged entropy change), and RCP (relative cooling power) with the values of 7.1 J/kg K, 6.8 J/kg K and 165.9 J/kg for ErCoSi2, as well as 8.7 J/kg K, 8.5 J/kg K and 152.9 J/kg for TmCoSi2, respectively, under ΔH (field change) of 0–50 kOe.