Unconventional critical behavior in room temperature magnetocaloric material: Fe30Cr45V25 all d-metal Heusler alloy

Comprehensive study on the critical behavior and magnetocaloric properties of Fe30Cr45V25 is carried out. The ferromagnetic alloy undergoes a second-order magnetic phase transition at TC = 300 K. The critical exponents of Fe30Cr45V25 are β = 0.380, γ = 1.293, and δ = 4.389. Although the obtained exponents do not fall into any conventional universal classes (slightly relatable with 3D Heisenberg type), they get renormalized around TC and obey the Widom scaling relation, ascribed to the reliability of the calculation. 3D Heisenberg type (isotropic) spin alignment is suggested by the renormalization group approach. However, the interaction strength is of long-range order. Further, the magnetic entropy change (ΔSm) and relative cooling power for an applied field of 70 kOe are −0.89 J kg−1 K−1 and 184.84 J kg−1 at 308 K. The system exhibits almost constant ΔSm over a broad temperature range with negligible hysteresis, a favorable feature for solid-state regenerators. [Display omitted] •Fe30Cr45V25 alloy undergoes a second order magnetic transition from paramagnetic to ferromagnetic around 300 K.•Critical exponents of the sample are studied and verified for the first time.•The studied all-d-metal Heusler alloy has 3D Heisenberg type isotropic spin alignment.•Interaction strength is of long-range order.•Magnetocaloric performance is also studied.