ISSN:
1551-2916
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Maschinenbau
,
Physik
Notizen:
High-temperature ionic conductivity of zirconia–calcia (ZrO2–CaO), zirconia–yttria (ZrO2Y2O3), and zirconia–rareearth-oxide (ZrO2RE2O3) solid solutions was measured at temperatures of 1000°–1600°C. The emf polarization method and a thermodynamic emf method using a new reference system (aluminum melt coexisting with solid alumina) were applied to obtain the parameters pe' characterizing ionic conductivity. In the present study, the parameter pe' has been investigated as a function of temperature, of dopant radius, of dopant concentration, and of conditions of preparation. In the range of the investigated dopant concentrations, parameter pe' was shown to decrease as the dopant radius decreased. For the system ZrO2Y2O3, a minimum of the parameter pe was observed at 25 mol% Y2O3. In addition to this, it is important to take into account the sintering parameters, the purity, and the grain size of the used samples to compare the results with previous data. A comparison of the parameter pe of CaO- and Y2O3-doped ZrO2 and of RE2O3-doped ZrO2 indicates that the relevant values of ZrO2RE2O3 solid solutions are one to two orders lower. Additional studies on new multicomponent solid solutions based on ZrO2 also revealed promising high-oxygen-ion-conductive solid electrolyte materials in view of low values of parameter pe. Wide ranges of cubic solid solutions were identified by X-ray diffractometry. It was demonstrated that the two experimental techniques can successfully be used to determine mixed ionic and electronic conduction in commonly used solid oxide electrolyte materials, e.g., for practical oxygen sensors in metal melts.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1151-2916.1997.tb02915.x
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