Synthesis and Characterization of Copper doped Nickel ferrite Prepared by Sol-gel Method

Cobalt-substituted ZnS QDs: a diluted magnetic semiconductor and efficient photocatalyst

“…It is usually seen that the conductivity increases initially for metal oxide nanomaterials with the increase in the applied electric eld frequency and then decreases further since the hopping frequency lags behind the eld frequency. 40,41 This type of behavior for ac electrical conductivity of our prepared QDs was also observed. It is noted that the total electrical conductivity (s t ) of transition metal oxide QDs is made up of both dc and ac conductivity parts as follows: [36][37][38] s t (T, u) = s dc (T) + s ac (T, u)…”

“…All the synthesized QDs were unable to hold the polarization as the applied field frequency increases, as they failed to follow the frequency variations. 38–41…”

“…All the synthesized QDs were unable to hold the polarization as the applied eld frequency increases, as they failed to follow the frequency variations. [38][39][40][41] Another important parameter, i.e., loss tangent which is a ratio of the imaginary component to the real component of dielectric constant, measures the polarization loss of a dielectric material. Dielectric losses are mostly caused by the existence of the point defects, cationic vacancies, grain boundaries, dopants, impurities and lattice imperfections in the dielectric material.…”

“…Normally, when these metal oxide nanomaterials are subjected to an alternating electric eld, the charge conduction occurs due to the hopping of electrons. [36][37][38][39][40] The applied ac eld gives electrons sufficient energy to break through the electrostatic barrier, successfully enabling the hopping process. It is usually seen that the conductivity increases initially for metal oxide nanomaterials with the increase in the applied electric eld frequency and then decreases further since the hopping frequency lags behind the eld frequency.…”

Dyes Degradation Using Cooper-Nickel Ferrite and Its Tunable Structural and Photocatalytic Properties

“…Figure 2 shows the infrared spectra of Ni x Cu (1-x) Fe 2 O 4 samples at room temperature. The high-frequency bands, for all samples, are positioned at a narrow range of wavenumbers (see the insert in Figure 2), which are characteristic of the formation of spinel ferrite structures [24]. The high-frequency band between 600 and 500 cm −1 is related to the stretching of metals in tetrahedral sites, while the high-frequency band close to 400 cm −1 corresponds to the stretching vibration in octahedral sites [25,26].…”