Ceramics based on SnO2, ZnO and Zn2SnO4 prepared by conventional and microwave sintering
Résumé
Materials based on SnO2, ZnO and Zn2SnO4 are due to its unique properties used in various applications such as gas sensors, varistors, electrodes, photoelectric devices, and others. In this contribution we present results on ceramics which were prepared from SnO2 and ZnO and also from their mixtures to obtain Zn2SnO4 phase. These ceramics were sintered from 900 to 1400 °C by conventional (CV) and microwave (MW) sintering. The ceramic microstructure was characterized by determining the phase composition, porosity, bulk density, and grain size. Apart from that, elastic properties of these ceramics were investigated at room temperature but also at high temperature to observe the conventional sintering behavior and temperature dependence of these properties. In the case of ceramics prepared from both oxides the creation of Zn2SnO4 was observed above 900 °C after both CV- and MW- sintering. However, microstructural descriptors such as porosity and bulk density were significantly different depending on the sintering process. Interesting observations occurred in the case of pure SnO2 ceramics, where the porosity and bulk density remained constant and no shrinkage occurred even at 1400 °C, but the elastic properties were significantly changing on samples sintered at higher temperatures. That is related to the non-densifying sintering mechanisms characteristic for this material.