Samanta, T.; Taake, C.; Caron, L.: Probing the skyrmion phase of MnSi through the field-exponent of the isothermal entropy change. Physical Review Materials 9 (2025), p. 064413/1-7
10.1103/1ftc-3xyw
Open Access Version
Abstract:
A detailed study of the field-induced entropy change evolution under hydrostatic pressure (𝑝 ) of the well-known skyrmion-hosting MnSi system was carried with the goal of assessing its magnetocaloric properties and identifying the skyrmion phase. The pressure-induced modification of the first-order phase transition boundary of the skyrmion phase in MnSi has been determined through the field-exponent, 𝑛(𝑇,𝐵) , of the isothermal entropy change [Δ𝑆𝛼(𝐵)𝑛] . The skyrmion phase boundaries generated from 𝑛(𝑇,𝐵) and ac-susceptibility data are in qualitatively good agreement at ambient pressure. The application of hydrostatic pressure can lower the transition temperature of MnSi towards the hydrogen liquefaction temperature (∼20 K) while retaining the first-order nature of the phase transition up to the highest applied pressure of 𝑝=9.8kbar . As a result, the studied system maintains good magnetocaloric properties near 20 K [|Δ𝑆|=4.24J/kgK , adiabatic temperature change |Δ𝑇ad|=4.62K (estimated), and refrigerant capacity |𝑅𝐶|=91.37J/kg for Δ𝐵=7T with 𝑝=9.8kbar] , which are comparable to those of light rare-earth Laves phase compounds with the added benefit of being composed of cheap and abundant elements.