Abstract:
(98.85-
x)SnO
2-1CoO-0.05Cr
2O
3-0.1Sb
2O
5-
xIn
2O
3 (
x=0, 0.05, 0.10, 0.15, mole fraction/%) Sb-based SnO
2 varistors were prepared by sintering SnO
2 powder, CoO powder, Cr
2O
3 powder, Sb
2O
5 powder and In
2O
3 powder at a pressure of 100 MPa and a temperature of 1 300 ℃. The effect of In
2O
3 doping amount on the microstructure and electrical properties of varistors was studied. The results show that with increasing In
2O
3 doping amount, the average grain size of Sb-based SnO
2 varistors decreased, the density increased first and then decreased, the nonlinear coefficient, applied density, interfacial state density and barrier height all increased first and then decreased, the leakage current density decreased first and then increased, and the voltage gradient increased. When the mole fraction of doped In
2O
3 was 0.10%, the varistor had the largest density of 6.82 g·cm
-3 and the excellent electrical properties with voltage gradient, nonlinear coefficient, leakage current density, applied density, interfacial state density and barrier height of 851 V·mm
-1,32.36,1.19 μA·cm
-2,4.4×10
23 m
-3,3.2×10
16 m
-2 and 1.44 eV, respectively.