Giant magnetocaloric effect in the quaternary Fe–Rh–Pd–Ir alloyGimaev, Radel (Avtor) Karpenkov, Alexey (Avtor) Shelkovyi, Fedor (Avtor) Chirkova, Alisa (Avtor) Schröder, Christian (Avtor) Zhezlyaev, Gleb (Avtor) Devyaterikov, Denis (Avtor) Vagov, Alexei (Avtor) Vasilyev, Dmitry (Avtor) Kolchugina, Natalia (Avtor) magnetocaloric effectadiabatic temperature changeFe-Rh alloysfirst-orderphase transitionfirst-principles calculationsThe magnetothermal properties of the quaternary Fe▫$_{49}$▫Rh▫$_{46.1}$▫Pd▫${3.1}$▫Ir▫$_{1.8}$▫ alloy are investigated by a combination of first-principles calculations, structural characterization, magnetometry, calorimetry, and direct measurements of the adiabatic temperature change. An exceptional magnetocaloric response is obtained, with ΔT▫$_{ad}$▫ reaching −11.9 K in a field of 1.85 T under the discontinuous protocol and −8.6 K under the continuous (cyclic) protocol, both values exceeding those reported to date for FeRh-based alloys under comparable conditions. The enhancement originates from a combination of structural and electronic properties: a nearly single-phase B2 composition, induced magnetic moments on Pd and Ir predicted by first-principles calculations, and a narrow magnetostructural transition (∼6 K). In addition, the present composition exhibits an exceptionally small thermal hysteresis of ∼6 K, which is among the smallest reported for the FeRh family and preserves a large magnetocaloric response under cyclic operation. The high transition temperature of ∼411 K further distinguishes the present composition from conventional near-room-temperature magnetocaloric systems. The temperature dependences of the lattice parameter, magnetization, heat capacity, and magnetocaloric response are presented and compared with literature data for binary and ternary FeRh-based alloys.20262026-08-17 14:41:33Članek v reviji185678UDK: 621.56:669.15ISSN pri članku: 0925-8388DOI: 10.1016/j.jallcom.2026.190307COBISS_ID: 287894019sl