Impact of silicon doping on the magnetocaloric effect of MnFeP0.35As0.65 powder

• MnFeP0.35As0.65−xSix series of compounds has been obtained by solid-state sintering.
• It was found that silicon improves adiabatic temperature change as well as magnetic entropy change.
• Significant increase of ΔTad has been found when silicon content was improved to x = 0.11.
• The highest ΔS=11 J/kg*K at B = 2T and ΔTad=3.2 K at B = 1.7T were estimated for the sample with Si amount x = 0.11.
• The ΔTad has been found to be 0.6 K higher during cooling regime due to the unique latent heat of sample (for x = 0.11).

The magnetocaloric effect in the MnFeP0.35As0.65−xSix intermetallic compounds, prepared via solid-state sintering was studied. Adiabatic temperature and magnetic entropy changes were obtained in order to characterize these compounds. The substitution of silicon for arsenic leads to a significant enhancement of the magnetocaloric effect for silicon amount x = 0.11. The adiabatic temperature change increased from 2.3 to 3.3 K for the magnetic field change from 0 to 1.7 T. This improvement has been correlated with the increase of crystalline cell volume and change of lattice constants. Additionally, the structure of pure MnFeP0.33As0.67 has been modeled in order to check the spin alignment within the framework of ferromagnetic collinear model.

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