Heat pump cycles based on the AF–F transition in Fe–Rh alloys induced by tensile stress

Abstract

The heat-pumping scheme based on the 1st order antiferromagnetism–ferromagnetism transition induced in FeRh alloy by one-dimensional tensile stress is proposed. Using the model S–T diagram for this alloy, the heat-pump cycles are drawn up based both on the transition latent heat absorption and emission when the transition is induced isothermally and on the change in alloy's temperature when the transition is induced adiabatically by applying tensile stress. The calculated values of heat coefficient φ for the cycles are ∼30 at Δ T=5 К and ∼20 at Δ T=10 К, where Δ T is the difference between the temperature surrounding and that of the heat receiver. These values are achieved using the tensile stress of ∼1·10 9 Pa. The high values of φ make it possible to consider Fe–Rh alloys near the equiatomic composition as an effective refrigerant for elastocaloric heat-pumping near the room temperature.