Influence of Annealing Atmosphere on Varistor Property of TiO<sub>2</sub>-Nb<sub>2</sub>O<sub>5</sub>-SrCO<sub>3</sub> Ceramics

Investigation The Effect of Particle Size and Annealing on the Performance of Nano/Micro Sized ZnO-Based Varistors

“…illustrates the collect of the presented frequencies of Raman active phonon modes of the ZnO-based varistor comparison with the theoretical results. One of the most intensive modes in the Raman spectrum of all samples is a very tight (2 cm −1 ) peak low at 99 cm −1 , referred to as vibrations of the zinc sub-lattice in ZnO [22,23,24]. The other very intensive Raman mode is E 2 high at 437 cm −1 mostly referred to as the oxygen vibration [22,23,24].…”

“…One of the most intensive modes in the Raman spectrum of all samples is a very tight (2 cm −1 ) peak low at 99 cm −1 , referred to as vibrations of the zinc sub-lattice in ZnO [22,23,24]. The other very intensive Raman mode is E 2 high at 437 cm −1 mostly referred to as the oxygen vibration [22,23,24]. Furthermore, the A 1 (LO) mode at 569 cm −1 and the E 1 (LO) mode at 586 cm −1 the presence of impurities and/or defects can influence both modes, the E 1 (LO) mode is more strongly affected by these effects [9].…”

“…Kunyong Kang and others investigated the effect of post-heat treatment on improving the structural of Ti -N -SrC Ceramics varistors. Their results showed a significant improvement in the properties of the samples that were annealed in oxygen for 3 hours at 750°C with nonlinear coefficient (α) = 8.9 and break-down voltage ( = 19.1 V•m [24]. Amal Boumezoued et al found that the microstructure and electrical properties of ZnO-Bi 2 O 3 varistors were improved when they annealed in a temperature range between 650 and 900 °C [25].…”

“…Recent research focuses on studying the factors that play an important role to make varistors more stable with low leakage current such as sintering temperature, the sintering period, and the type of sintering [13,14,15]. Annealing process is a heat treatment used to modify the microstructure to improve the crystallization and get rid of defects in material which involving slowly cooling the sample after heating at a specific temperature for a while to achieve a near equilibrium condition of characteristics [24]. Many researchers studied the effect of post annealing in different environments on improving the microstructure and homogeneity of grains and increasing their size, which inevitably affects the performance of varistors [1,2,14,15].…”

Effects of Dopants and Processing Parameters on the Properties of ZnO-V2O5-Based Varistors Prepared by Powder Metallurgy: A Review

“…MOVs are sintered ceramic materials typically manufactured in a disc shape that resembles a right circular cylinder, although rectangular or hexagonal prism shapes with flat surfaces are reported less frequently [ 4 ]. MOVs are complex, multicomponent systems that consist of a semiconducting oxide [ 5 ] such as zinc (II) oxide (ZnO) [ 6 , 7 , 8 , 9 ], tin (IV) oxide (SnO 2 ) [ 10 , 11 ], or titanium (IV) dioxide (TiO 2 ) [ 12 , 13 ] as the main component (>90 mol.%), and multiple MO additives as minor components.…”