In this work, the sol-gel process in non-aqueous system of tetraethylorthosilicate (TEOS) has been investigated. The formation of spherical silica nanoparticles was studied using 1H and 13C NMR, FTIR spectroscopies and TEM. It was demonstrated that FTIR, TEM and 1H NMR can be employed to monitor effectively the conversion of TEOS into insoluble SiO2 from the supersaturation of hydrolyzed monomers. This leads to the formation of colloidal silica primary particles. The optimized sol-gel parameters allow to produce the monodisperse spherical silica particles suitable for the development of technology for antireflection coatings.

In this study, lanthanide metal-organic frameworks Ln(BTC)(DMF)₂(H₂O) (LnMOFs) are synthesized using the metal nitrates as lanthanide (Ln = La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and Lu) source and 1,3,5-benzenetricarboxylic acid (BTC) as a coordination ligand. X-ray diffraction (XRD) analysis, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric (TG/DTG) analysis fluorescence spectroscopy (FLS), and scanning electron microscopy (SEM) are employed to characterize the newly synthesized LnMOFs.

In this study, an aqueous sol-gel synthesis method and subsequent dip-coating technique were applied for the preparation of yttrium iron garnet (YIG), yttrium iron perovskite (YIP), and terbium iron perovskite (TIP) bulk and thin films. The monophasic highly crystalline different iron ferrite powders have been synthesized using this simple aqueous sol-gel process displaying the suitability of the method. In the next step, the same sol-gel solution was used for the fabrication of coatings on monocrystalline silicon (100) using a dip-coating procedure. This resulted, likely due to substrate surface influence, in all coatings having mixed phases of both garnet and perovskite. Thermogravimetric (TG) analysis of the precursor gels was carried out. All the samples were investigated by X-ray powder diffraction (XRD) analysis. The coatings were also investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Mössbauer spectroscopy. Magnetic measurements were also carried out.

In this study, the aqueous sol-gel method was employed for the synthesis of (1−x)SrTiO₃-xBiMnO₃ solid solutions. Powder X-ray diffraction analysis confirmed the formation of single-phase perovskites with a cubic structure up to x = 0.3. A further increase of the BiMnO₃ content led to the formation of a negligible amount of neighboring Mn₃O₄ impurity, along with the major perovskite phase. Infrared (FT-IR) analysis of the synthesized specimens showed gradual spectral change associated with the superposition effect of Mn-O and Ti-O bond lengths. By introducing BiMnO₃ into the SrTiO₃ crystal structure, the size of the grains increased drastically, which was confirmed by means of scanning electron microscopy. Magnetization studies revealed that all solid solutions containing the BiMnO₃ component can be characterized as paramagnetic materials. It was observed that magnetization values clearly correlate with the chemical composition of powders, and the gradual increase of the BiMnO₃ content resulted in noticeably higher magnetization values.