Crystalline, magnetic, cobalt ferrite nanoparticles were synthesized from an aqueous solution containing metal nitrates and polyvinyl pyrrolidone (PVP) as a capping agent by a thermal treatment followed by calcination at various temperatures from 673 to 923 K. The structural characteristics of the calcined samples were determined by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and transmission electron microscopy (TEM). A completed crystallization occurred at 823 and 923 K, as shown by the absence of organic absorption bands in the FT‐IR spectrum. Magnetization measurements were obtained at room temperature by using a vibrating sample magnetometer (VSM), which showed that the calcined samples exhibited typical magnetic behaviors.

This study reports the simple synthesis of MFe₂O₄ (where M=Zn, Mn, and Co) nanoparticles by a thermal treatment method, followed by calcination at various temperatures from 723 to 873 K. Poly(vinyl pyrrolidone) (PVP) was used as a capping agent to stabilize the particles and prevent them from agglomeration. The characterization studies were conducted by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The average particle sizes were obtained by TEM images, which were in good agreement with the XRD results. Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of metal oxide bands for all the calcined samples. Magnetic properties were demonstrated by a vibrating sample magnetometer (VSM), which displayed that the calcined samples exhibited superparamagnetic and ferromagnetic behaviors.

The thermal treatment method was employed to prepare nickel-cobalt oxide (NiO/Co₃O₄) nanoparticles. This method was attempted to achieve the higher homogeneity of the final product. Specimens of nickel-cobalt oxide were characterized by various experimental techniques, including X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). X-ray diffraction results showed that there was no crystallinity in the predecessor, and it still had the amorphous phase. The formations of the crystalline phases of the nickel-cobalt oxide nanoparticles started from 350–500 °C, and the final products had different crystallite sizes ranging from 11–35 nm. Furthermore, the variation of DC conductivity (σ_dc), impedance, tangent loss (tgδ) and dielectric constant (ε′) of the calcined specimens with frequency in the range of 10²–10⁶ Hz was investigated. σ_dc showed a value of 1.9 × 10⁻⁶ S/m, 1.3 × 10⁻⁶ S/m and 1.6 × 10⁻⁶ S/m for the specimens calcined at 350, 400 and 450 °C, respectively. Additionally, a decrease in tgδ values with an increase in temperature was observed. Finally, the formed nanoparticles exhibited ferromagnetic behaviors, which were confirmed by using a vibrating sample magnetometer (VSM).

Nickel ferrite nanocrystals were prepared from an aqueous solution containing metal nitrates and various concentrations of poly(vinylpyrrolidone) followed by calcination temperature. X-ray diffraction (XRD) analysis was performed to determine the degree of crystallinity of the ferrite nanoparticles. By transmission electron microscopy, the morphology and average particle size of the nickel ferrite nanoparticles were evaluated which had good agreement with the XRD results. Fourier transform infrared spectroscopy suggested the presence of metal oxide bands in all samples as well as the effective elimination of organic constituents after calcinations. Measurements of the extent of magnetization of the nickel ferrite nanoparticles synthesized in different concentrations were obtained at room temperature using a vibrating sample magnetometer.

In The present project, a variety of MnFe₂O₄ (Mn) and Cr₂Fe₆O₁₂ (Cr)-based nanocarriers (NCs) were synthesized as photosensitizer and NCs for delivery of chemotherapeutic curcumin (CUR) and provide a new structure for Photodynamic Therapy (PDT). For determining efficiency of NCs release study, MTT assay, lethal dose test and hemolysis assay were carried out. The release study showed the release of CUR from NCs was pH-dependent, but, every NCs had its own behavior for releasing the drug. The data acquired from the release study showed the CUR release from Mn can reach to over 90% at acidic media instead of 41% at neutral media. However, the CUR released from Cr were approximately equal as Cr had equal zeta potential at both media. Hemolysis activity and lethal dose test displayed the cytotoxicity of NCs was neglectable at both in vitro and in vivo study. Also, the results of anti-cancer activity assay (MTT assay) showed that both of Cr and Mn NCs are suitable systems for PDT. Therefore, the results demonstrated that Mn is suitable NCs for PDT and anticancer drugs delivery of therapeutic drugs.

Zinc ferrite nanocrystals were prepared from an aqueous solution containing metal nitrates and various of concentrations of poly(vinyl pyrrolidone) (PVP), i.e., 0, 15, 40, and 55 g/L, as a capping agent. To stabilize the particles, they were thermally treated at 873 K, as an optimum calcination temperature. The behaviors of the polymeric precursor were analyzed by use of simultaneous thermo-gravimetry (TG) and derivative thermo-gravimetry analyses (DTG). The presence of the crystalline phase in each sample was confirmed by X-ray diffraction (XRD) analysis. The average particle size and the morphology of the nanoparticles were determined by transmission electron microscopy (TEM), and these parameters were found to differ at various concentrations of PVP. Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of metal oxide bands for all the PVP concentrations and confirmed the absence of organic bands for PVP concentrations less than 55 g/L. Measurements of the magnetization value of the zinc ferrite nanoparticles were obtained at room temperature by using a vibrating sample magnetometer (VSM), which showed that, in the absence of PVP, the sample exhibited a paramagnetic behavior while, in the presence of PVP, samples have a super-paramagnetic behavior.