Tunable Curie temperature around room temperature and wide temperature span of magnetic entropy change in (Fe1-xMnx)2Y compounds

The structure, Curie temperature (T-C) and magnetic entropy change (Delta S-M) of (Fe1-xMnx)(2)Y (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6) compounds were investigated by x-ray powder diffraction (XRD) and magnetization measurements. All compounds crystallize in single phase with cubic MgCu(2-)type structure and present second-order phase transitions from ferromagnetic to paramagnetic state at T-C. The substitution of Mn for Fe in the Fe2Y system results in the drastic decrease of T-C from T-C = 519 K for x = 0 to T-C = 78 K for x = 0.6. The maximum values of |Delta M-S| as well as broad working temperature spans are obtained under a field change from 0 to 5 T, which are 1.65, 1.27 and 1.17 J kg(-1).K for x = 0.3, 0.4 and 0.5, respectively. The corresponding relative cooling power (RCP) values are evaluated to be 90.29, 84.98 and 63.29 J kg(-1). The present results may give some clue for searching new materials with large magnetocaloric effect.