Ionic conductivity of sodium beta″-alumina☆
1981; Elsevier BV; Volume: 2; Issue: 4 Linguagem: Inglês
10.1016/0167-2738(81)90027-8
ISSN1872-7689
AutoresHerbert Engstrom, J.H.T. Bates, W.E. Brundage, Jun Wang,
Tópico(s)Thermal Expansion and Ionic Conductivity
ResumoMeasurements of the electrical conductivity of Na ß″-alumina show that the low-temperature activation energies are 0.3337 ± 0.0055 eV for MgO stabilized crystals grown at 1700°C, 0.275 ± 0.015 eV for crystals with the same starting composition position grown at 1650°C, and 0.1716 ± 0.0093 eV for crystals stabilized with ZnO and grown at 1700°C. The conductivities of almost all crystals at 500°C were found to be 1.3 ± 0.6 Ω−1 cm−1. In addition to the growth conditions, the presence of a dc electric field, the type of electrode material, the type of conducting ion, and the concentration of stabilizing ion are important in determining the electrical conductivity. These factors are believed to affect the nature of the ordering of vacancies in the ß″-aluminas, leading to variations in the activation energy.
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