Sb-doped ZnO ceramics: NTC thermistors with high temperature sensitivity and electrical stability

摘要

Sb-modified ZnO ceramics (Zn_(1-x)Sb_xO, x = 0, 0.001, 0.003, 0.005, 0.007, 0.010, 0.015, 0.020, 0.025) were prepared by the conventional solid-state reaction process. The phase component, electrical properties and electrical stabilities were investigated. Zn_(1-x)Sb_xO ceramics have hexagonal wurtzite structure and show typical characteristics of negative temperature coefficient of resistivity. The room temperature resistivity and temperature sensitivity can be adjusted by Sb element doping. For various contents of Sb-ions, the prepared ceramics have temperature sensitivity of B_(25/85) values from 2284 to 4754 K. After aging treatment at 150 °C, the ceramics have resistance change rates (ΔR/R_0) ranging from 1.44 to 2.17%. The aging induced change of resistance mainly resulted from the grain effect. The aging characteristics were discussed with the complex impedance spectra of ceramics and the variation of valent states of Sb-ions before and after aging.