Impact of W doping on Fe-rich (Mn,Fe)&lt;sub&gt;2&lt;/sub&gt;(P,Si) based giant magnetocaloric materials

Zhang, F.; Smits, Sebastian; Kiecana, A.; Batashev, I.; Shen, Q.; van Dijk, N.H.; Brück, E.H.

doi:10.1016/j.jallcom.2022.167802

Impact of W doping on Fe-rich (Mn,Fe)₂(P,Si) based giant magnetocaloric materials

Title

Impact of W doping on Fe-rich (Mn,Fe)₂(P,Si) based giant magnetocaloric materials

Author

Zhang, F. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Smits, Sebastian (Student TU Delft)
Kiecana, A. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Batashev, I. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Shen, Q. (TU Delft RST/Fundamental Aspects of Materials and Energy)
van Dijk, N.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Brück, E.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)

Date

2023

Abstract

The influence of doping with the 5d transition metal W has been studied in the quaternary (Mn,Fe)₂(P,Si) based giant magnetocaloric compounds, which is one of the most promising systems for magnetic refrigeration. It is found that W substitution can separately decrease the Curie temperature T_C and retain the thermal hysteresis ∆T_hys at an almost constant level (∼5 K) for Mn_0.6Fe_1.27-xW_xP_0.64Si_0.36 (x ≤ 0.02). Low-content W doping conserves the good magnetocaloric effect (MCE) without an obvious degradation. For x ≤ 0.02 the average magnetic entropy change |∆S_m| amounts to 11.4 Jkg⁻¹K⁻¹ for an applied magnetic field change of 2 T and the adiabatic temperature change ∆T_ad amounts to 3.9 K for an applied magnetic field change of 1.5 T. The occupancy of substitutional W atoms is determined by XRD experiments and DFT calculations. Our studies provide a good strategy to further optimize the MCE of this material family.