The influence of the mechanical activation of ZnO nanoparticle fillers on the structural and electrical properties of the matrix of poly(vinylidenefluoride)–ZnO (PVDF–ZnO) films was investigated. Transmission electron microscopy and scanning electron microscopy analyses showed that mechanical activation in a high energy planetary ball mill reduces the size of ZnO particles. X-ray diffraction and Raman spectroscopy revealed that PVDF crystallized predominantly as the γ -phase. Non-activated ZnO filler reduces the degree of the crystallinity of the matrix and promotes crystallization of α -phase of PVDF in the film, while the fillers activated for 5 and 10 min induce crystallization of β -phase, indicating that mechanical activation of the filler can be used as a general method for fabrication of PVDF composites with increased content of piezoelectric β -phase crystals. Dielectric spectroscopy measurements show that polymer composite with the high content of β -phase (with ZnO filler activated for 5 min) exhibits the highest value of dielectric permittivity in 150–400 K range of temperatures. Kinetic analysis shows combined effects of increased surface area and increased concentration of surface defects on the interactions between polymer chains and activated nanoparticles.

${\text{V}}_2{\text{O}}_3$ nanocrystals can be synthesized through hydrothermal reduction in $\text{VO}{\left(\text{OH}\right)}_2$ using hydrazine as a reducing agent. Addition of different ligands to the reaction produces nanoparticles, nanorods, and nanoplatelets of different sizes. Small nanoparticles synthesized in this manner show suppression of the magnetic phase transition to lower temperatures. Using muon spin relaxation spectroscopy and synchrotron x-ray diffraction, we have determined that the volume fraction of the high-temperature phase, characterized by a rhombohedral structure and paramagnetism, gradually declines with decreasing temperature, in contrast to the sharp transition observed in bulk ${\text{V}}_2{\text{O}}_3$.