22 KB893 KB20 KB199219991999Bernik, SlavkoDaneu, Ninaletnik:33številka:66 stranistr. 487-492ISSN:1318-0010COBISSID:205226URN:URN:NBN:SI:doc-0HSVJRJLenInštitut za kovinske materiale in tehnologijeŽelezarna JeseniceŽelezarna RavneŽelezarna ŠtoreKovine zlitine tehnologijebizmutov oksidceramiccinkov oksidelektrične lastnostikeramikakositrov oksidmikrostrukturasintranjeCharacteristics of SnO2 doped ZnO-Bi2O3 ceramics| Značilnosti SnO2 dopirane ZnO-Bi2O3 keramike|The influence of ?$SnO_2$? additions on the sintering, microstructure development and nonlinear characteristics of ZnO based ceramics in the ZnO-?$Bi_2O_3-SnO_2$? system was studied. Introduction of ?$SnO_2$? to the ZnO-?$Bi_2O_3$? system results in the formation of the ?$Bi_2Sn_2O_7$? type pyrochlore phase and the ?$Zn_2SnO_4$? type spinel phase. For Sn/Bi < ratio the pyrochlore phase forms and bounds all the ?$SnO_2$?, while excess ?$Bi_2O_3$? results in the formation of a liquid phase at 740°C which enhances sintering. In samples with a Sn/Bi > 1 ratio all the ?$Bi_2O_3$? is bounded in ?$Bi_2Sn_2O_7$? pyrochlore phase and sintering is hindered. Sintering is promoted after decomposition of the pyrochlore phase into a ?$Bi_2O_3$? melt and ?$Zn_2SnO_4$? type spinel phase at temperatures above 1000°C. The addition of 0.1% of ?$SnO_2$? promotes ZnO grain growth. In compositions with larger amounts of ?$SnO_2$?, growth of ZnO grains is already inhibited by the increasing amount of ?$Zn_2SnO_4$? type spinel phase. Moderate doping with ?$SnO_2$? improved nonlinear characteristics of the basic ZnO- ?$Bi_2O_3$? binary system, while a large amount of ?$SnO_2$? resulted in its degradationPreiskovali smo vpliv dodatka ?$SnO_2$? na sintranje, razvoj mikrostrukture in tokovno-napetostno nelinearnost keramike na osnovi ZnO v sistemu ZnO-?$Bi_2O_3-SnO_2$?. Pri dodatku ?$SnO_2$? v sistem ZnO-?$BIi_2O_3$? pride do nastanka piroklorne faze tipa ?$Bi_2Sn_2O_7$? in spinelne faze tipa ?$Zn_2SnO_4$?. Pri razmerju Sn/Bi < 1 piroklorna faza ?$Bi_2Sn_2O_7$? veže ves ?$SnO_2$?, preostali ?$Bi_2O_3$? pa povzroči pri 740°C nastanek tekoče faze, ki pospeši sintranje. v vzorcih z razmerjem Sn/Bi > 1 je ves ?$Bi_2O_3$? vezan v piroklorno fazo, zato je sintranje zavrto. Sintranje v teh vzorcih je pospešeno, ko pride pri temperaturi nad 1000°C do razpada piroklorne faze v talino ?$Bi_2O_3$? in spinelno fazo ?$Zn_2SnO_4$?. Dodatek 0,1% ?$SnO_2$? pospeši rast zrn ZnO. Pri sestavah z večjim dodatkom ?$SnO_2$? je rast zrn že zavrta zaradi vedno večje količione spinelne faze ?$Zn_2SnO_4$?. Zmerni dodatki ?$SnO_2$? izboljšajo nelinearno karakteristiko binarnega sistema ZnO - ?$Bi_2O_3$?, večji dodatki pa jo poslabšajoTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije