A Study on Optical and Dielectric Properties of Ni-ZnO nanocomposite

Significantly Suppressed Dielectric Loss and Enhanced Breakdown Strength in Core@Shell Structured Ni@TiO2/PVDF Composites

“…Figure 2 a demonstrates the XRD curves of pristine Ni and Ni@TiO 2 particles. First, the XRD peaks in the curve of pristine Ni can well correspond to the lattice planes of Ni particles, for example, 44.5° (110), 51.8° (200) and 76.3° (220) [ 42 ]. Compared with the pristine Ni particles, the peaks intensity of Ni@TiO 2 dramatically decline and several new peaks at 27.4° (110), 36.2° (101), 54.3° (211) and 69.1° (301) related to the lattice planes of TiO 2 are observed [ 43 ].…”

“…The gradually decreased permittivity in Ni@TiO 2 /PVDF systems can be explained as follow. The semi–conductor TiO 2 with a wide forbidden band effectively prevents the charge carrier’s migration between pristine Ni particles, efficaciously promoting the formation of leakage current, and remarkably declining space charge polarization [ 42 , 43 , 44 , 45 , 46 ]. However, compared to PVDF, the Ni@TiO 2 /PVDF composites still exhibit much large permittivity.…”

Effect of frequency on the classical and relaxor ferroelectric behavior of substituted titanate Ba0.7Er0.16Ca0.05Ti0.91Sn0.09O3

“…The following equation is used to derive the actual grain capacity (Cg) from the constant phase elements Q . 45 C = Q 1/ n R (1+ n )/ n where n is the exponent of the frequency whose value determines whether the behavior of the material is resistive or capacitive.…”

Low-Temperature Spin-Canted Magnetism and Bipolaron Freezing Electrical Transition in Potential Electron Field Emitter NdNiO3

“…The conductivity in the middle- and low-frequency zone is found to be weakly frequency-dependent, and it is associated with the first and second terms of eq . The sharp change of electrical conductivity near MIT from 150 to 300 K is associated with some peculiar carrier concentration-driven polaronic transport mechanism, where bipolaron condensation takes place across the insulating phase, as reported by Shamblin et al The conductivity spectra in this region are described by the CTRW model for a disordered solid where τ e is the characteristics of carrier hopping time. This model is not used broadly yet and has been applied in some rare earth transition metal oxide compounds near MIT so far. Above the room temperature in the metallic region above 300 K, the ac conductivity (σ) is investigated by conventional Jonscher power-law formulas, where σ 0 (dc) represents the dc conductivity; A and n (0 < n < 1) stand for temperature- and material property-dependent coefficient and frequency exponent, respectively. The frequency-independent plateau in low-frequency regions is associated with dc conductivity, and its contribution gradually developed with thermal treatment.…”

“…Above the room temperature in the metallic region above 300 K, the ac conductivity (σ) is investigated by conventional Jonscher power-law formulas,…”