Study on the structure and electrical behaviour of zinc aluminate ceramics irradiated with gamma radiation

Abstract

The preparation process of zinc aluminate (ZnAl2 O4) ceramic powder, as well as the sintering temperature have been consequently governed using scanning electron microscopy (SEM) and x-ray diffraction (XRD) techniques. A broad exothermic peak in the range 223–310 °C is observed due to the crystallization of ZnAl2O4 powder. Then the final resultant powder was irradiated with gamma rays at different doses from 30 to 150 kGy. The effect of gamma irradiation on the structure and the electrical behaviour of ZnAl2O4 ceramics has been obtained. The induced changes in the structure have been studied via SEM, XRD and FTIR spectrometers. The obtained results reveal no changes in the spinel phase of ZnAl2O4, while some displacements of the constituent individual atoms for the irradiated samples are observed. The I–V characteristic curves and the dielectric properties of the prepared ceramic powder have been measured for unirradiated and irradiated samples. These curves exhibit nonlinearity of this type of ceramics, where the dc current gradually increases with the increase in the dose. The irradiation of ZnAl2O4 with gamma radiation was found to increase the nonlinearity of the I–V curves. The dielectric constant and loss were found to decrease as the dose increases. Therefore, the irradiation of ZnAl2O4 with gamma rays can improve its utility as an electronic protector in electrical circuits against sudden overvoltage.

Role of Gas Doping Sequence in Surface Reactions and Dopant Incorporation during Atomic Layer Deposition of Al-Doped ZnO

“…31,32 Peaks denoted by asterisks (*, **) correspond to modes expected for materials containing Zn-O-Al bond units. 33,34 As R This suggests that the aluminum species readily mix with the ZnO over the thickness associated with 4 cycles of ZnO deposition. This is consistent with the QCM results that show that TMA affects the subsequent DEZ/H 2 O mass uptake for ∼4 ALD cycles.…”

“…The incident angle allows both the transverse (TO) and longitudinal optical (LO) modes to be observed . The peaks of the ZnO TO and LO, and the Al 2 O 3 LO modes are indicated at 402, 576, and 950 cm −1 , respectively. , Peaks denoted by asterisks (*, **) correspond to modes expected for materials containing Zn−O−Al bond units. , As R D/Z increases, features associated with Zn−O bonding decrease. Features related to Al−O bonding are not observed in any of the ZnO:Al films studied, but features are observed for Zn−O−Al.…”

Zinc Aluminate-Based Composite Nanoparticles for Microwave Applications

“…The excellent thermal strength, mechanical resistance, and small surface acidity of ZnAl 2 O 4 allow it to be employed as a catalyst support. 5 ZnAl 2 O 4 is a semiconductor material with an optical band gap of 3.8 eV. Various methods have been reported in the literature to prepare nanoparticles, including solid-state reactions, co-precipitation, hydrothermal techniques, sol–gel methods, etc.…”

“…The cubic cell is made up of 32 oxygen atoms with tetrahedral and octahedral cations. The excellent thermal strength, mechanical resistance, and small surface acidity of ZnAl 2 O 4 allow it to be employed as a catalyst support . ZnAl 2 O 4 is a semiconductor material with an optical band gap of 3.8 eV.…”

Fabrication and Characterization of TiO₂-Doped ZnAl₂O₄ Nanocrystals via Sol-Gel Method for GPS Antenna

“…The bands observed in the low-frequency region of the spectrum 487-550 cm -1 correspond to the ZnO, TiO 2 and AlO 6 . Furthermore, for the un-doped TiO 2 , the band correspond to the bending mode of ZnO and AlO 6 which is the built up of ZnAl 2 O 4 spinel appeared at 487 cm -1 [22]. Band at 487 and 550 cm -1 for x=0.05 to 0.25, the spinel band almost disappeared because of affected from the doping material (TiO 2 ).…”