Bimetallic Fe-Ni nanoalloys for magnetic hyperthermia: Correlating structural evolution, magnetic properties, and...

Magnetic hyperthermia has emerged as one of the promising techniques for localized cancer treatment through heat generation by applying an alternating magnetic field (AMF) in soft ferromagnetic nanoparticles. In this work, bimetallic Fe-Ni nanoalloys are synthesized and systematically investigated to understand the structural evolution along with its magnetic properties and heating capability by introducing Fe into Ni alloy. X-ray diffraction (XRD) demonstrates a composition driven transition from Face Centered Cubic (FCC) to coexisting FCC and BCC structure with an increase in Fe content. High resolution Scanning Electron Microscopy (HRSEM) analysis confirms the formation of quasi-spherical nanoparticles with moderate agglomeration, while DLS and zeta potential analyses indicate larger hydrodynamic size and moderate colloidal stability of the ferrofluid. Magnetic measurements demonstrate soft ferromagnetic behavior with high saturation magnetization (M_s) and low coercivity (H_c) irrespective of measuring temperatures, confirming thermal stability. Among the investigated ferrofluids, 2 mg/ml formulation effectively reaches the hyperthermia threshold, and 2.5 mg/ml exhibits the maximum specific absorption rate (SAR) of 236.03 W/g within 800 s. Preliminary cytocompatibility assessment using NIH 3T3 cells shows acceptable cell viability. These findings highlight the potential of Fe-Ni nanoalloys as promising candidates for magnetic hyperthermia application, subject to further detailed biological validation.