Self-regulating magnetic hyperthermia by magnetostructural phase transformation of magnetic-shape-memory Ni–Mn–Cu-Ga Heusler-type particles

Magnetic hyperthermia is a non-invasive cancer therapy method resulting in cell apoptosis. The method is based on generating heat by magnetic nanoparticles in external magnetic fields. One of the main challenges however is to control the temperature of the particles to avoid overheating which would also damage healthy tissues. Here, we introduce magnetic-shape-memory Heusler particles as a potential self-regulating magnetic hyperthermia agent thanks to a sharp reversible magnetostructural phase transformation. We demonstrate that Ni–Mn–Cu-Ga particles can be designed to heat-up to a desired temperature (by high-frequency alternating magnetic fields), above which they undergo the phase transformation, therefore, lose their magnetic properties and the capability of magnetic-field-induced heating, thereby showing a “self-regulating” magnetic hyperthermia effect. We analyze the obtained data by numerical calculations, highlighting the major heat dissipation mechanisms and the critical role of sharpness of the magnetostructural phase transformation (martensite – austenite) in Ni49.7Mn18.7Cu6.4Ga25.2 on the self-regulation effect. Besides, we show the effects of air pressure, power input, dispersant and starting temperature on the attained final equilibrium temperature.