While materials with a 1st order Curie transition (T C) are known for the magnetic cooling effect due to the reversibility of their large entropy change, they also have a great potential as a candidate material for induction heating where a large loss power is required under a limited alternating magnetic field. We have carried out a proof-of-concept study on the induction heating effect in 1st order ferromagnetic materials where the temperature is self-regulated at T C. LaFe11.57Si1.43H1.75, a well-known magnetocaloric material, was employed in this study because T C of this compound (319 K) resides in the ideal temperature range for hyperthermia treatment of cancerous cells. It is found that the hysteresis loss of LaFe11.57Si1.43H1.75 increases dramatically near T C due to the magnetic phase coexistence associated with the 1st order magnetic transition. The spontaneous magnetization (M s) shows a very abrupt decrease from 110 Am2kg−1 at 316 K to zero at 319 K. This large M s immediately below T C along with the enhanced irreversibility of the hysteresis curve result in a specific absorption rate as large as 0.5 kWg−1 under a field of 8.8 kAm−1 at 279 kHz. This value is nearly an order of magnitude larger than that observed under the same condition for conventional iron oxide-based materials. Moreover, the large heating effect is self-regulated at the 1st order T C (319 K). This proof-of-concept study shows that the extraordinary heating effect near the 1st order Curie point opens up a novel alloy design strategy for large, self-regulated induction heating.
