Gd5Si4 is a promising candidate for magnetic hyperthermia because its T-C is near the therapeutic range and is tuneable, opening the door for self-regulated hyperthermia, which is limited from overheating by T-C. In addition, Gd5Si4 has a high saturation magnetization and is potentially biocompatible. In this paper, Gd5Si4 particles were fabricated by a scalable top-down approach of arc-melting and ball-milling. The particles have an average size of 900 nm and a wide size range. Magnetization measurements show that the magnetic transition is broadened and the transition temperature T-C is somewhat reduced from the bulk value of 63 degrees C to 50 degrees C, which is very close to the maximum desired hyperthermia temperature range of 43 degrees C-45 degrees C. Hyperthermia measurements were performed in an alternating magnetic field. Specific loss power was calculated from the slope of the heating curve; the maximum value was 18 W/g at 0.064 T and 213 kHz. Self-regulated heating behavior was demonstrated, with maximum temperatures approaching 47 degrees C for the largest fields, close to the measured magnetic transition temperature T-C.
Gd5Si4 Micro- and Nano-Particles for Self-Regulated Magnetic Hyperthermia