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Abstract This study presented the use of SrTiO₃/Y₂O₃nanoparticles for the reinforcement of dental poly(methyl methacrylate) (PMMA) to enhance its mechanical properties important for everyday use of denture base materials. The average crystallite size of prepared nanoparticles was 19.9 nm. The influence of 0.5, 1.0, and 1.5 wt% SrTiO₃/Y₂O₃loading on absorbed impact energy, microhardness and tensile properties was investigated. Scanning electron microscopy of the composite fracture surface revealed multiple toughening mechanisms, with agglomerates directly included in the crack pinning, indicating improvement in mechanical performance. Dynamic mechanical analysis proved that agglomerates improved the elastic behavior of PMMA and confirmed the absence of a residual monomer. After the incorporation of SrTiO₃/Y₂O₃, the mechanical properties of composites showed a high increase compared to neat PMMA. The optimal concentration of nanoparticles was 1 wt%, for which the microhardness, modulus of elasticity, and absorbed impact energy were higher by 218.4%, 65.8% and 135.6%, respectively. With such a high increase, this research showed that SrTiO₃/Y₂O₃represents an efficient filler which use does not have to be limited to dental materials. HighlightsSrTiO₃/Y₂O₃hybrid nanoparticles were prepared.PMMA‐SrTiO₃/Y₂O₃composite showed increase in impact resistance up to 135.4%.Elastic behavior of PMMA was improved.With 1 wt% of SrTiO₃/Y₂O₃, microhardness increased by 218.4%. 

BaTiO 3 (BTO) is considered the most commonly used ceramic material in multilayer ceramic capacitors due to its desirable dielectric properties. Considering that the miniaturization of electronic devices represents an expanding field of research, modification of BTO has been performed to increase dielectric constant and DC bias characteristic/sensitivity. This research presents the effect of N 2 and air atmospheres on morphological and dielectric properties of BTO nanoparticles modified with organometallic salt at sintering temperatures of [Formula: see text]C, [Formula: see text]C, [Formula: see text]C, and [Formula: see text]C. Measured dielectric constants were up to 35,000, with achieved very high values in both atmospheres. Field emission scanning electron microscopy (FESEM) was used for morphological characterization, revealing a porous structure in all the samples. The software image analysis of FESEM images showed a connection between particle and pore size distribution, as well as porosity. Based on the data from the image analysis, the prediction of dielectric properties in relation to morphology indicated that yttrium-based organometallic salt reduced oxygen vacancy generation in N 2 atmosphere. DC bias sensitivity measurements showed that samples with higher dielectric constant had more pronounced sensitivity to voltage change, but most of the samples were stable up to 100 V, making our modified BTO a promising candidate for capacitors. 

The BaTiO3 ceramics applications based on electronic properties have very high gradient scientific and industrial-technological interests. Our scientific research has been based on nano BaTiO3 modified with Yttrium based organometallic salt (MOD-Y). The samples have been consolidated at a sintering temperature of 1350 °C. Within the study, the new frontiers for different electronic properties between the layers of BaTiO3 grains have been introduced. The research target was grain boundary investigations and the influence on dielectric properties. After scanning electron microscopy and dielectric measurements, it has been established that modified BaTiO3 samples with larger grains showed a better compact state that led to a higher dielectric constant value. DC bias stability was also investigated and showed a connection between the grain size and capacitance stability. Analyses of functions that could approximate experimental curves were successfully employed. Practical application of fractal corrections was performed, based on surface (αs) and pore size (αp) corrections, which resulted in obtainment of the relation between the capacitance and Curie temperature. Successful introduction of fractal corrections for capacitance-Curie temperature dependence for a set of experimental data is an important step towards further miniaturization of intergranular capacitors.