In this study, the effect of sintering temperature on the phase composition, density, microstructure, and mechanical properties of multidoped zirconia-toughened alumina (MZTA) ceramics containing multidoped zirconia (Zr_0.90(Y, Ce, Ca, Mg)_0.10O₂) was investigated. The samples were fabricated using a conventional ceramic processing and sintered at temperatures ranging from 1400 to 1600 °C for 5 h. X-ray diffraction and whole-powder-pattern fitting (WPPF) analysis showed that, regardless of the sintering temperature, the samples consisted predominantly of t-ZrO₂ and Al₂O₃ phases, with a minor (0.7–2.8 wt. %) amount of m-ZrO₂ detected at certain temperatures. Scanning electron microscopy revealed that increasing the sintering temperature from 1400 to 1600 °C resulted in an increase in the average Al₂O₃ grain size from 0.39 to 1.32 µm and the ZrO₂ grain size from 0.28 to 0.92 µm. The sample sintered at 1500 °C exhibited the best combination of microhardness (HV5 1748) and flexural strength (620 MPa), owing to its high density and homogeneous microstructure. At higher sintering temperatures, abnormal grain growth accompanied by a decrease in density was observed, resulting in a reduction in flexural strength. The fracture toughness (K_IC) showed an approximately linear increase with increasing sintering temperature.

Often, when describing the electromagnetic properties of polymer composites in the microwave range, little attention is paid to magnetic spectra and the description of their features using known dispersion models. In this paper, we investigate the microstructure and frequency spectra of the complex permittivity and complex permeability of the ferrite-polymer composite PVDF/Ni_0.4Zn_0.6Fe₂O₄ in the frequency range of 100 MHz–5 GHz and a mass concentration of 10–80 wt.%. The composite structure was investigated by scanning electron microscopy, while the frequency dependences of permittivity and magnetic permeability were measured using a vector network analyzer together with the Nicholson–Ross–Weir method. In the course of the work, using the fitting of the experimental spectra by known models of natural ferromagnetic resonance and domain wall resonance, the features of the dispersion of the magnetic spectra were explained. In particular, the shift of resonance frequency and the dominant contribution of spin rotation to the permeability value were interpreted using the results of fitting. In addition, comparison of the features of the reflection loss spectra and the results of model fitting helped to identify the main contribution of the spin rotation process to the attenuation of the electromagnetic wave in composites. The results obtained in the work are relevant for the development of new approaches to predicting the electromagnetic characteristics of composites using effective medium models.