UNIAXIAL-STRESS DEPENDENCE OF THE IONIC-CONDUCTIVITY OF SOME ALKALI-HALIDES

A sensitive method to measure ionic conductivity changes of uniaxially stressed crystals is described. The stress effect in the extrinsic regime of the conductivity of NaCl and LiF single crystals is used to determine the elastic dipole tensor of a migrating cation vacancy. The elastic dipole tensor is transformed to the double force tensor which gives insight into the jump path the ion takes and into the elastic displacements in the immediate neighbourhood of the jumping ion.