Akademik Veri Yönetim Sistemi
Micro and Nanostructures, cilt.216, 2026 (SCI-Expanded, Scopus)
Large-scale perovskite applications require a lead-free matrix with tolerable properties. Rare earth doping can be an effective way to achieve an enhanced performance. While previous studies have primarily focused on low rare-earth doping levels, research into reaching the maximum solubility limit of the guest rare earth into the perovskite host is still notably sparse. This work investigates the structural, morphological, magnetic, electrical, and dielectric properties of lead-free BaTiO3 (BTO) perovskite ceramic modified with high weight fractions (2–20 wt%) of amphoteric Yb2O3. X-ray diffraction (XRD) analysis revealed a composite-like microstructure where Yb2O3 persists as a separate phase across all concentrations, while the host lattice exhibited an oscillatory volume response, highlighting the amphoteric transition of Yb3+ ions between A and B sites. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDX) mapping revealed typical quasi-spherical and polyhedral BTO grains alongside irregular Yb2O3 precipitates. The magnetization versus applied magnetic field (M(H)) analysis showed hysteresis loops, reflecting ferromagnetic behavior of the samples, likely governed by the bound magnetic polaron (BMP) model. The electrical and dielectric properties of BaTiO3/xYb2O3 ceramics were also systematically examined over a temperature range from 20 °C to 120 °C. AC conductivity exhibits characteristic dispersive behavior tracking universal Jonscher power law (UJPL), confirming a thermally activated hopping conduction explained by the correlated barrier hopping (CBH) model. The frequency exponent (0 ≤ s ≤ 1) reduces with rising temperature, indicating enhanced charge-carrier mobility. DC conductivity obeys Arrhenius performance, with the activation energy greatly dependent on additive concentration; moderate Yb2O3 contents (2–10 wt%) improve charge transport, while higher concentrations stimulate defect-induced carrier trapping. A pronounced reduction in dielectric constant (from ∼1500 to ∼5–20) is observed due to the construction of a composite microstructure and dominance of ferroelectric polarization. In the meantime, the dielectric loss and dissipation factor are significantly diminished. Impedance analysis reveals non-Debye relaxation, dominated by grain-boundary and interfacial effects. These findings demonstrate that Yb2O3 modification and composite formation provide an effective strategy for tailoring the electrical performance of BaTiO3 ceramics for advanced dielectric applications.