Abstract
Large magnetic entropy change |ΔS| with a nearly temperature-independent magnitude over a wide temperature range (about 70 K span from ∼140 K to 210 K) was observed in an Fe-based NaZn13-type compound LaFe11.375Al1.625. Such a behavior of magnetic entropy change is ascribed to two closely spaced magnetic transitions. One at 181 K (TN) with second-order nature is from the paramagnetic to antiferromagnetic state; another at 140 K (TO) with first-order nature, temperature hysteresis ∼5 K, is from antiferromagnetic to ferromagnetic state. At the antiferromagnetic to ferromagnetic transition a large change of resistance was found, which can be induced as a function of temperature as well as field. The magnetoresistence under a field of 1 T reaches 3.4%.