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Measurements of Electromotive Force in Al 2 O 3 ‐Pitfalls and Results
Author(s) -
YEE J.,
KRÖGER F. A.
Publication year - 1973
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.1151-2916.1973.tb12453.x
Subject(s) - electromotive force , crystallite , thermal conduction , emf measurement , ionic bonding , materials science , thermocouple , grain boundary , single crystal , condensed matter physics , crystal (programming language) , electrode , analytical chemistry (journal) , mineralogy , chemistry , crystallography , electrical engineering , physics , ion , composite material , microstructure , metallurgy , organic chemistry , chromatography , electrolyte , engineering , programming language , computer science
When guards are used to eliminate surface and gas conduction in emf measurements, thermocouple effects of the electrodes and guards must be taken into account, and unwanted gradients in gas composition must be eliminated. Results for single‐crystal and polycrystalline Al 2 O 3 are given. Single crystals have an ionic transference number, t̄ l of ≅1, with a possible small decrease as a result of electronic (hole) conduction at T >1450°C. Polycrystalline samples exhibit t i values of