EFFECT OF MG DOPING ON DIELECTRIC-PROPERTIES OF ALUMINA

Alumina samples with different magnesia concentrations between 0.02 an d 1 wt% have been sintered and characterized by electron microscopy. T heir dielectric properties between 1 kHz and 15 GHz are studied. Diffe rent dielectric behaviors are found for different magnesia concentrati ons. A model based mainly on dipolar relaxation processes is proposed to explain the results obtained. The effect of magnesia on dielectric properties of alumina shown in the present work should be considered i n the engineering designs for heating systems of future fusion machine s and other applications. (C) 1996 American Institute of Physics.