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The nonstoichiometric Fe₂P-type FeMn_(1-x)V_x(P_0.5Si_0.5)_1-x alloys (x = 0, 0.01, 0.02, and 0.03) have been investigated as potential candidates for magnetic refrigeration near room temperature. The magnetic ordering temperature decreases with increasing FeV concentration x, which can be ascribed to decreased ferromagnetic coupling strength between the magnetic atoms. The strong magnetoelastic coupling in these alloys results in large values of the isothermal entropy change (ΔS_M); 15.7 J/(kg K), at 2 T magnetic field for the x = 0 alloy. ΔS_M decreases with increasing x. Results from Mössbauer spectroscopy reveal that the average hyperfine field (in the ferromagnetic state) and average center shift (in the paramagnetic state) have the same decreasing trend as ΔS_M. The thermal hysteresis (ΔT_hyst) of the magnetic phase transition decreases with increasing x, while the mechanical stability of the alloys improves due to the reduced lattice volume change across the magnetoelastic phase transition. The adiabatic temperature change ΔT_ad, which highly depends on ΔT_hyst, is 1.7 K at 1.9 T applied field for the x = 0.02 alloy.