Sequential Synthesis Methodology Yielding Well-Defined Porous SrTiO/NiFeO Nanocomposite.

In this research, we reported on the formation of highly porous foam SrTiO/NiFeO (STO/NFO) heterostructure by joint solid-state and sol-gel auto-combustion techniques. The colloidal assembly process is discussed based on the weight ratio x (x = 0, 25, 50, 75, and 100 wt %) of NiFeO in the STO/NFO system. We proposed a mechanism describing the highly porous framework formation involving the self-assembly of SrTiO due to the gelation process of the nickel ferrite. We used a series of spectrophotometric techniques, including powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), N adsorption isotherms method, UV-visible diffuse reflectance spectra (UV-Vis DRS), vibrating sample magnetometer (VSM), and dielectric measurements, to investigate the structural, morphological, optical, magnetic, and dielectric properties of the synthesized samples. As revealed by FE-SEM analysis and textural characteristics, SrTiO-NiFeO nanocomposite self-assembled into a porous foam with an internally well-defined porous structure. HRTEM characterization certifies the distinctive crystalline phases obtained and reveals that SrTiO and NiFeO nanoparticles were closely connected. The specific magnetization, coercivity, and permittivity values are higher in the STO/NFO heterostructure and do not decrease proportionally to the amount of non-magnetic SrTiO present in the composition of samples.