Structural, Magnetic, and Magnetothermal Properties of Co100−xNix Nanoparticles for Self-Controlled Hyperthermia

Abstract

In this study, the structural and magnetic properties of a series of functionalized Co100−xNix (x = 20, 30, 40, 50, 60, 80, 85) nanoparticles (NPs) were analyzed with the objective of attaining a high specific absorption rate (SAR). The magnetic nanoparticles (MNPs) obtained by ball milling at 1425 rpm lie in the range of 03–29 nm and are studied as potential candidates for magnetic fluid hyperthermia. Magnetic measurements show that all samples possess soft ferromagnetic properties with the reduction in the Curie temperature (TC) by Ni substitution in Co100−xNix alloys and by ball milling. The specific absorption rate (SAR) and specific loss power (SLP) obtained from magnetothermal measurements for powder and fluid samples lie in the range 4.4–83 W/g and 19–382 W/g, respectively, showing strong dependence on structural and magnetic properties. The SAR/SLP values as a function of the applied field at 425 kHz display a square dependence on the applied magnetic field below 165 Oe, which is expected for single domain ferromagnetic nanoparticles, but deviate from this at higher values of the applied field. We also obtained the effective anisotropy constant Keff for ball-milled nanoparticles at 1425 rpm for 200, 300, and 500 min. within the framework of linear response theory, showing strong dependence on average crystallite size. Additionally, the toxicity of the prepared nanoparticles in the form of percentage hemolysis was controlled with oleic acid.

Metal and Metal Oxides Nanoparticles and Nanosystems in Anticancer and Antiviral Theragnostic Agents

“…Furthermore, NPs of magnetic metal alloys were used to optimize the magnetic properties. For the MHT needs, as magnetic agents Fe [52], Co [53] NPs and Fe-Ni-Co [54], Co-Ni [55], Fe-Au [56][57][58], Fe-Al [59], Fe-Rh [60], Fe-Cr-Nb-B [61], Cu-Fe and Cu-Ni [62] alloys are considered. The potential chemical instability and toxicity of Co and Ni limit their use.…”

MOF-Derived Hetero-Zn/Co Hollow Core-Shell TMOs as Anode for Lithium-Ion Batteries

“…The biphasic Co 3 O 4 /Fe 3 O 4 hollow nanospheres prepared from Fe@Co-MOFs exhibited a specific capacity of 937 mAh g −1 after 150 cycles at 0.1 A/g, and their structures remained in good condition after 150 cycles [10]. The porous hollow nanostructures of MOF-derived material can provide 3D interconnected channels for the rapid transfer of Li + , increase the contact area between the electrode and the electrolyte, as well as provide additional internal space for volume change [11][12][13][14]. Based on the above studies, it is feasible and promising to synthesize multi-metal TMOs with regular shapes using MOFs as precursors.…”