Characterization of new negative temperature coefficient thermistors based on Zn–Ni–O system

Abstract

Y 2 O 3 -doped Zn 1x Ni x O (x = 0, 0.3, 0.4, 0.5, 0.6, 0.7, and 0.9) powders were prepared by a wet chemical synthesis method, and the related ceramics were obtained by the traditional ceramic sintering technology. The phases and related electrical properties of the ceramics were investigated. The analysis of X-ray diffraction (XRD) indicates that the prepared ceramics with Ni substitution have a cubic crystalline structure. The resistance-temperature feature indicates that all the ceramics show a typical effect of negative temperature coefficient (NTC) of resistivity with the thermal constants between 3998 and 5464 K, and have high cyclical stability in a temperature range from 25 to 300 ℃. The impedance analysis reveals that both grain effect and grain boundary effect contribute collectively to the NTC effect. The electron hopping and band conduction models are proposed for the grain (bulk) conduction, and the thermally activated charge carrier transport overcoming the energy barrier is suggested for the grain boundary conduction.

Tailoring the properties of Ni-Mn based NTC thermistors by Cu and Li addition

“…This can be used to transform the resistance versus temperature function of a thermistor into a linear lnR versus T 1 function. The average slope of this function would then yield an approximation of the B parameter value [1,8,[34][35][36]. The set of graphs with 1/T on the X-axis and lnR on the Y-axis were plotted to obtain the thermistor parameters.…”

“…T is the temperature in Kelvin and R is the resistance in ohms. In the measurement of temperature in the range of 200 °C, the error in the Steinhart-Hart equation is usually less than 0.02 °C[1,8,[34][35][36].…”

Structural and Electrical Properties of Zn1-xCrxO NTCR Nanoceramics Synthesized by High Energy Ball Milling

“…Because of its unique properties like non-toxic nature, abundance in nature, low cost, suitability for doping, high thermal and chemical stability and is an important semiconductor materials [9]. ZnO has versatile applications like UV photodetectors [10] gas sensors [11], solar cells [12], spintronics [13] luminescent materials [14], piezoelectric devices [15], light emitting devices [16], Thermistor [17] and cancer treatment [18].…”

“…Chromium has been utilized to upgrade the optical, electrical, magnetic and luminescent behaviour of ZnO [38]. By doping ZnO with different metals like Ni [17], Sr [20], Ca [39], Mn [40], La [41] etc. into ZnO shows NTCR behaviour which is very much suitable for thermistor application.…”