The temperature dependences of heat expansion, elastocaloric effect, magnetocaloric effect, and the shift in the critical temperature of the transition due to tensile stress have been measured using samples of the same concentration Fe49Rh51 in the antiferromagnetic-ferromagnetic (AF-F) transition range. Using data on specific heat and magnetocaloric effects, entropy-temperature diagrams for the alloy were made for various magnetic fields. The ratios ΔS(TcH)/TcH, where ΔS(TcH) is the entropy change during transition and TcH is the transition’s critical temperature, were found to be ∼3.98×102 erg/g K2 which is close to the value of the change in the electronic specific heat coefficient Δγ obtained by other researchers. It has been concluded that the change in the electronic part of entropy is the main mechanism of the transition. The phenomenological model is proposed, taking into account the electronic entropy change during the transition. Calculations using the model give values for the main thermodynamic parameters of the transition (free energy change ΔF=1.91×106 erg/g, the critical temperature shift ∂Tc/∂P=3.08×10−9 K cm2/Dyn and ∂Tc/∂H=0.788 K/kOe due to hydrostatic pressure and magnetic field respectively), which are in agreement with experimental data.

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A cooling scheme based on the first‐order antiferromagnetism–ferromagnetism transition induced in the Fe–Rh alloy by one‐dimensional tensile stress is proposed. Using the model S–T diagram for this alloy, the cooling cycles are drawn up based both on the latent heat of transition absorption and emission when the transition is induced isothermally and on the change in temperature of the alloy when the transition is induced adiabatically by applying tensile stress. The calculated values of the efficiency ε for the cycles are ∼35 at ΔT = 5 K and ∼27 at ΔT = 10 K, where ΔT is the difference between the temperature of the surroundings and that of the cooled body. These values are achieved using a tensile stress of ∼1 × 109 Pa. The high values of ε make it possible to consider Fe–Rh alloys near the equiatomic composition as an effective refrigerant for elastocaloric cooling near room temperature.