Characterization of Additive‐Modified Beta Alumina Ceramics by Nuclear Magnetic Resonance

Abstract

Sintered compacts of beta alumina have been made with additives of Li 2 O, MgO, NiO, CaO, and Y 2 O 3 . The motional narrowing and quadrupole interactions of sodium were investigated as a function of temperature and additive concentration by wide‐line NMR. The Li 2 O, MgO, and NiO additives are incorporated in the beta alumina structure and enhance Na motion; CaO dissolves and inhibits Na motion; and Y 2 O 3 forms a second phase and has no effect on the Na. The effects of the additives are explained by the size and charge of the additive cation, and intragranular and intergranular conductivity in doped beta alumina ceramics are predicted.