Magnetocaloric effect in Fe-based amorphous alloys and their composites with low boron content

The amorphous soft magnetic Fe88Zr11B1 ribbon was fabricated and the magnetocaloric effect of it was investigated through the measurement of magnetization in this work. To enhance its magnetocaloric effect, Co is selected as a microalloying addition to this precursor. Among these ribbons, the replacement of Fe by minor Co, compared with the replacement of Zr by Co, gives more increment in Curie temperature and magnetic entropy change. Fe86Zr11B1Co2 exhibits the largest peak value of magnetic entropy change of 1.73 Jkg−1 K−1 and Fe88Zr9B1Co2 shows the largest refrigerant capacity of 149.7 Jkg−1 for an applied field of 15 kOe. Furthermore, a significant magnetic entropy change can be obtained using multiphase materials in this work. Under a magnetic field change of 15 kOe, the maximum improvement of the refrigerant capacity by 38.6%, in comparison with those of the individual alloys, is obtained for the layered composite of Fe88Zr11B1 (50 wt%) and Fe86Zr11B1Co2 (50 wt%). Besides, a quite broad SM(T) curve around room temperature of the amorphous composite is observed, which is a key feature for an Ericsson magnetic refrigeration cycle.