Effects of Hydrostatic Pressure on Magnetostructural Transitions and Magnetocaloric Properties in (MnNiSi)₁₋ₓ (FeCoGe)ₓ

The isostructural alloying of two compounds with different magnetic and thermo-structural properties has resulted in a new system, (MnNiSi)(1-x)(FeCoGe)(x), that exhibits large magnetocaloric effects with acute sensitivity to both compositional variation and applied hydrostatic pressure. The maximum isothermal entropy change reaches a value of -Delta S-max - 143.7 J/kg K for a field change of Delta B - 5 T at atmospheric pressure. The first-order magnetostructural transition responsible for the entropy change shifts to lower temperature with applied hydrostatic pressure (similar to-10 K/kbar) but maintains a large value of -Delta S-max.