Effect of SnO2 doping on microstructural and electrical properties of ZnO–Pr6O11 based varistor ceramics

Abstract

a b s t r a c tZnO-Pr 6 O 11 based varistor ceramics doped with 0-2.0 mol% SnO 2 were fabricated by sintering samples at 1300 • C for 2 h with conventional ceramic processing method. X-ray diffraction analysis indicated that the doped SnO 2 reacted with praseodymium oxides during sintering, generating Pr 2 Sn 2 O 7 phase. Through scanning electron microscopy, it was found that the doping of SnO 2 played a role against the growth of ZnO grains. Capacitance-voltage analysis revealed that the doped SnO 2 acted as a donor in the varistor. The measured electric-field/current-density characteristics of the samples showed that the varistor voltage increased with the increase of SnO 2 doping content, when the SnO 2 content was no more than 1.0 mol%; with the SnO 2 content up to no more than 0.5 mol%, the doping of SnO 2 could increase the nonlinear coefficient; but, when the SnO 2 doping content was further increased, the nonlinear coefficient and varistor voltage of the samples decreased, and the leakage current increased.

SnO2 Doping Effect on the Microstructural and Electrical Behavior of ZnO nanoparticles-Bi2O3 Based Varistor Ceramics

“…Figure 1 exhibits the differences of the apparent and relative densities of the varistor ceramics with various SnO 2 doping amounts. The apparent density of the varistors also raised obviously with the SnO 2 adding amounts up to 1.5 mol%, which may be attributed to the greater density of SnO 2 (6.995 g/cm 3 ) than that of ZnO (5.672 g/cm 3 ) as reported by Feng H., et al [7], and a few raise of relative density also observed (Figure 1). The huge ZnO discs densification at the high SnO 2 doping contents might be attributed to the SnO 2 doping impacts within the grain lattice, which led to the oxygen vacancies formation during the sintering step.…”

Microstructure and electrical properties of Y(NO3)3·6H2O-doped ZnO–Bi2O3-based varistor ceramics

“…Varistors can detect and limit high transient voltage surges and can repeatedly endure such surges [1,2]. They are usually used to sense and limit transient voltage surges.…”

“…They are usually used to sense and limit transient voltage surges. ZnO varistor ceramics show a highly nonlinear current-voltage characteristic with a highly resistive state in the pre-breakdown region that has a large non-linear coefficient [1][2][3][4][5][6][7][8][9][10]. Zinc oxide-based varistor ceramics are widely used in electronic appliances, such as voltage surge's protection devices, and especially in high-voltage lines.…”

Electrical Properties at Grain Boundaries Influenced by Cr3+Diffusion in SnO2.ZnO.Nb2O5-Films Varistor Prepared by Electrophoresis Deposition

“…For I vs V analysis, the Eq. 4 was used to check the nonlinear coefficient of curves [7,8]. α = (log E 2 -log E 1 ) -1 (4) where E 1 is the electrical field when current density is 1 mA/cm 2 and E 2 is the electrical field when current density is 10 mA/cm 2 .…”