Premium
High‐Temperature Ionic Conduction in Multicomponent Solid Oxide Solutions Based on Zirconia
Author(s) -
Weyl Axel,
Janke Dieter
Publication year - 1997
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1997.tb02915.x
Subject(s) - dopant , solid solution , materials science , cubic zirconia , ionic conductivity , ionic radius , yttria stabilized zirconia , fast ion conductor , analytical chemistry (journal) , oxide , electrolyte , doping , ionic bonding , sintering , conductivity , atmospheric temperature range , mineralogy , inorganic chemistry , ceramic , ion , chemistry , thermodynamics , metallurgy , electrode , physics , optoelectronics , organic chemistry , chromatography
High‐temperature ionic conductivity of zirconia–calcia (ZrO 2 –CaO), zirconia–yttria (ZrO 2 Y 2 O 3 ), and zirconia–rareearth‐oxide (ZrO 2 RE 2 O 3 ) 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 p e' characterizing ionic conductivity. In the present study, the parameter p e' 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 p e' was shown to decrease as the dopant radius decreased. For the system ZrO 2 Y 2 O 3 , a minimum of the parameter pe was observed at 25 mol% Y 2 O 3 . 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 Y 2 O 3 ‐doped ZrO 2 and of RE 2 O 3 ‐doped ZrO 2 indicates that the relevant values of ZrO 2 RE 2 O 3 solid solutions are one to two orders lower. Additional studies on new multicomponent solid solutions based on ZrO 2 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.