WEB LiNbO3: Model ferroelectric oxide or unique compound?Tuesday (22.09.2020) 10:55 - 11:10 F: Functional Materials, Surfaces, and Devices 2 Part of:
After five decades of dedicated research, LiNbO3 has become one of the most intensively investigated ferroelectrics. The effort of the ferroelectric community has lead to unprecedent deep insight (and open issues) in the physical mechanisms that determine the materials properties. It is however still to be settled whether the knowledge collected on LiNbO3 is generally valid, or strictly material specific. In order to answer this question, we investigate and compare (theoretically and ex- perimentally) fundamentally different aspects of LiTaO3 and LiNbO3. First principles calculations reveal the existence of point defects in LiTaO3 compatible with the polaronic picture established in LiNbO3. Luminescence and absorption spectroscopy measurements show very similar dynamics and spectral features in LiNbO3 and LiTaO3. Elec- trical conductivity measurements demonstrate the existence of a low temperature and a high temperature regime for the two materials, from which rather similar activation energies can be extrapolated. The re- sults suggest that the knowledge of the physical mechanisms gathered on LiNbO3 can be transferred to other ferroelectric oxides such as LiTaO3 and related solid solutions.