Synthesis Mechanism of Low-Voltage Praseodymium Oxide Doped Zinc Oxide Varistor Ceramics Prepared Through Modified Citrate Gel Coating
نویسندگان
چکیده
High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr(6)O(11)) based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr(6)O(11) addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr(6)O(11) from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, α, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and α lowering with increasing Pr(6)O(11) content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary.
منابع مشابه
Effect of Co3O4 doping on nonlinear coefficient in Zn-Bi-Ti-O varistor ceramics
In the ZnO based varistor, the improvement of nonlinear coefficient (α) and prevention of evaporation of Bi2O3 during heat treatments can be achieved by the addition of MnO2 or Co3O4. In this conjunction, it is proper to see the effect of these additives at different low mol percentage and sintering conditions to nonlinear coefficient improvement of the varistor ceramics. In this paper, the inv...
متن کاملVaristor performance of nanocrystalline Zn–Bi–O thin films prepared by reactive RF magnetron sputtering at room temperature
The Zn–Bi–O films were deposited by reactive radio frequency magnetron sputtering in oxygen atmosphere from ZnBi alloy target (wt% ratio Zn:Bi=9:1) on glass substrate at room temperature. The XRD patterns show that the films deposited on tin-doped indium oxide/glass substrates were nanocrystalline. The microstructure of Bi-doped ZnO films was studied by scanning electron microscopy in combinati...
متن کاملSynthesis and Characterization of Zn-doped and un-doped SnO2 nanostructures for PV Applications
Tin oxide nanostructures, un-doped and Zn-doped, have been prepared by conventional sol-gel technique. Research grade tin chloride (SnCl2.2H2O) and zinc acetate (Zn(O2C2H3)2) were used as tin and zinc sources. Ethylene glycol and alcohol were used as solvents under different synthesis conditions. Transparent un-doped and Zn-doped SnO2 sol was prepared after continuous stirring and refluxing at ...
متن کاملSynthesis, characterization, and gas sensing properties of In-doped ZnO nanopowders
Indium (1at %) doped ZnO and ZnO nanoparticles have been synthesized via sol gel method. The structural characters of the synthesized nanoparticles have been studied by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM) and energy-dispersiveX-ray spectroscopy (EDX). From synthesized nanopowders a tablet was prepared by using the isostatic pressing and then sintered at ...
متن کامل