ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract In this article, electron emission is used to study the defect structure of α alumina. The need of a direct measurement of the position of the Fermi level (or the electron concentration in the conduction band) is shown by discussing the actual electrical data on alumina. The emission has been measured over a large temperature range (1400 to 2400 K) and the emission of a technical polycrystalline alumina is reported up to the melting temperature under a controlled oxygen partial pressure. Additional results are reported for titanium- and iron-doped polycrystalline aluminas. The results are discussed from two points of view. First the quantitative data concerning the work function are taken into account and the contribution of the surface layer is discussed. Secondly, the dependency of the electron emission on the oxygen partial pressure is explained by the defect chemistry of the oxide. The absence of variation of the electron concentration in a certain range of $$P_{{\text{O}}_{\text{2}} }$$ is due to a self compensation between donor and acceptor impurities.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01058088
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