Microwave Synthesis and Magnetocaloric Effect in AlFeB.

A promising magnetic refrigerant, AlFeB, has been prepared for the first time by microwave (MW) melting of a mixture of constituent elements. For comparison, samples of AlFeB have been also prepared by arc-melting, traditionally used for the synthesis of this material, and by induction (RF) melting, which was used in the very first report on the synthesis of AlFeB. Although an excess of Al has to be used to suppress the formation of ferromagnetic FeB, the other byproduct, AlFe, is easily removed by acid treatment, affording phase-pure samples of AlFeB.