Large magnetic entropy change in compound LaFe/sub 11.44/Al/sub 1.56/ with two magnetic phase transitions

Abstract

It is shown that Fe-based compound LaFe/sub 11.44/Al/sub 1.56/ with cubic NaZn/sub 13/-type structure undergoes both a second order and a first order phase transitions. In small fields, it orders antiferromagnetically at T/sub N/=186 K, and ferromagnetism is established at T/sub 0//spl ap/127 K. At T>T/sub 0/, field-induced metamagnetic transition between the two phases is observed in larger fields. The magnetic entropy change |/spl Delta/S|, estimated as a function of temperature from magnetization curves, has large values near the first-order transition. Metamagnetic transformation leads to an asymmetric broadening of the maximum with increasing field. This compound may be useful for magnetic refrigeration.