Przejście fazowe antyferroelektryk - paraelektryk w niestechiometrycznym $NaNbO_3$

Abstract

The theory of AFE-PE phase transformation as formulated by Kittel is reviewed. The experimental values obtained from dielectric measurements are related, to the parameters of Kittel's thermodynamic function. Some of the parameters has been determined for nonstoichimetric $NaNbO_3$. It is found that the excess of sodium in samples influences strongly the phase transformation.