Dopant effect on trapping charge properties studied by the mirror method correlated with Cp measurement

We investigate the dopant effect of silver on detrapping charge properties in charged alumina samples. This effect is studied by measurement of the variation of specific heat, as a function of the temperature, correlated with the characterization of the embedded charge by the mirror method. CRICERAM sapphire contains high energy sites of trapping leading to a charging capacity even at room temperature. Silver atoms introduced in the sapphire create perturbations in the alumina lattice which change locally the polarizability leading to new polaron sites. The detrapping temperature corresponding to silver sites indicates that these sites are deeper than those in undoped sapphire. These results illustrate the role of local variation of polarizability on trapping