Investigation of Cr³⁺ doped Zn-Co nanoferrites as potential candidate for self-regulated magnetic hyperthermia applications

Abstract

Controlling the Curie temperature (TC) in the range from 42-46 °C in magnetic hyperthermia (MH) therapy is an essential research topic because overheating can cause irreversible damage to healthy tissue. When TC is in the above temperature range, the magnetic nanoparticles reach a paramagnetic state, effectively turning off the MH treatment. In this work, we synthesized Zn-Co nanoparticles of representative composition Zn0.54Co0.46CrxFe2-xO4, where the Fe3+ cations are carefully replaced by Cr3+ ions, which allow a precise tuning of TC and hence the self-regulation of MH. The X-ray diffraction analysis of the prepared nanoparticles confirms the formation of a single-phase cubic spinel structure. The average crystallite of the nanoparticles increases with Cr3+ doping, while the TC and saturation magnetization decrease considerably from 78 °C (x = 1) to 27 °C (x = 0.6) and 46.6 emu/g (x = 1) to 15.3 emu/g (x = 0.6), respectively. Besides MH potential of the investigated samples as revealed from specific absorption rate (SAR) assays and the maximum temperature reach (Tmax), vary from 7 W/g and 37.3 °C, for x = 0.6, to 38 W/g and 62.9 °C, for x = 0.1, we found that the composition Zn0.54Co0.46Cr0.4Fe1.6O4 is more promising with SAR of 22 W/g and Tmax = 42.3 °C, which is precisely lies in the safe temperature range to automatically activate the self-regulation during the magnetic hyperthermia treatment. The results reveal an excellent combination between size distribution and Cr3+ content in Zn-Co-based ferrite, which has a great potential for self-regulated magnetic hyperthermia applications.

Investigation of structural, electrical, and magnetic variations of Ni-Zn-Co ferrites by substituting rare earth Ho3+ for high-frequency applications

“…This is because the W-H approach tends to yield higher strain values by considering diffraction data over the full range and incorporating lattice dislocations [46]. The scattering observed in the data set about the nanocrystallite size, as reported here, aligns with findings in existing literature [21][22][23]. In summary, our detailed XRD analysis using the W-H model provided valuable insights into the size and strain effects in our samples, highlighting the Analysis of the XRD data (table 3) reveals that the lattice constant (A) initially increases up to a Ho 3+ ion concentration of 0.1 and then decreases with further increases in Ho 3+ ion concentrations.…”

“…Their technological potential is underscored by their suitability for diverse applications such as targeted microwave devices, sensors, magnetic recording, and drug delivery systems [15][16][17][18][19]. Consequently, numerous researchers have directed their focus towards exploring the capabilities of NZC ferrites [20][21][22][23].…”