Sequential Synthesis Methodology Yielding Well-Defined Porous 75% SrTiO 3 / 25% NiFe 2 O 4 Nanocomposite.

In this research, we reported on the formation of highly porous foam SrTiO 3 /NiFe 2 O 4 ( 100-x STO/ x 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 NiFe 2 O 4 in the 100-x STO/ x NFO system. We proposed a mechanism describing the highly porous framework formation involving the self-assembly of SrTiO 3 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 2 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 3 -NiFe 2 O 4 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 3 and NiFe 2 O 4 nanoparticles were closely connected. The specific magnetization, coercivity, and permittivity values are higher in the 75 STO/ 25 NFO heterostructure and do not decrease proportionally to the amount of non-magnetic SrTiO 3 present in the composition of samples.