Investigation Of Physical Properties And Applications Of Strong-correlated Materials LaTiO₃ And NdTiO₃

Motivated by the extensive researches in the discovery of high temperature superconductivity, more and more research groups have been taking interest in strong-correlation materials LaTiO3 and NdTiO3 because the metal-insulator transitions with doping appear. Most reports have been focusing on doped-LaTiO3 (NdTiO3) with bivalence ions such as Sr2+, Ba2+ and Ca2+. With the increasing of such doping level, the number of 3d electron changes from 3d1 to 3d0. Amow has ever claimed that La1-xSrxTiO3 would undergo two metal-insulator transitions from the parent compounds LaTiO3 to SrTiO3. An alternative method to change the valence of Ti atom is modulating the oxidation of LaTiO3+δor NdTiO3+δ. The method is of substantial significance with respect to the investigation of electronic properties of these systems. Moreover, although thin film is preferable in semiconducting application and industry, the reports of LaTiO3+δand NdTiO3+δthin film are scarce.In the first part of the dissertation, the structural and transport properties of LaTiO3+δ/2 epitaxial thin films, grown at different oxygen pressures ranging from 6.6×10-4 Pa to 5 Pa, have been investigated. X-ray diffraction peaks of the films shift to low angles with increasing oxygen pressure, indicative of variation of the...