Random electronic effects in ferroelectric lattices: An example

The determination of D.C. conductivities and of the related activation energies have been made in pure, reduced and doped BaTiO3 Remeika monocrystals. The luminescence and absorption data are used in connection with the previous results to explain the charge transfers in the ferroelectric phase. The conventional point of views (banding, hopping) are found unsufficient to explain the experimental results. The existence of correlated multielectron hopping close to a ferroelectric phase transition, impurity conduction of the Miller-Abraham's type, the role of the disorder (and its origin) on the two previous problems are discussed.