Preparation And Physical Properties Of Titanium Oxide Superconducting Thin Films

Transition metal oxides have rich electronic properties and phase transition characteristics,which play an important role in the exploration of superconductors.As a representative of transition metal oxides,titanium oxides have many kinds of oxides.At present,there are mainly TiO,Ti407,?-Ti3O5 and TiO,Ti2O3,?-Ti3O5 three-phase eutectic films,and their superconducting transition temperatures are 7.65K,3.0K,7.1K,6.3K,respectively.The preparation of high-quality titanium oxide films is the premise of studying its superconductivity.Titanium oxide thin films were prepared on sapphire substrate by pulsed laser deposition,and the superconductivity of the thin films was confirmed by an electrical transport test.In order to find out the optimal conditions for film growth,we studied the effects of pressure and temperature,annealing temperature,substrate annealing temperature,film thickness,and background atmosphere on the superconducting properties of films.Finally,the superconducting transition temperature reached 9K.The superconductivity of the films is related to the concentration of the carrier,and the field effect regulation can change the concentration of the carrier without changing the lattice structure.In the work,the electric transport properties of titanium oxide under the electric field were studied.The electric field of ±5V was applied to the films,and the results showed that the electric field had a very weak regulation effect on the titanium oxide films.Ion implantation is to inject high-energy ions into the films,which will remain in the target material after collision with the films and induce the films to produce defects.The superconductivity characteristics of titanium oxides are closely related to oxygen defects.It is found that the superconducting transition temperature decreases with the increase of the injection dose of He+ ions into the films.In addition,XPS analysis on the surface and interior of the films shows that only Ti4+ is found on the surface of the films,and Ti4+,Ti3+,Ti2+ are found in the interior of the films.Moreover,with the increase of pressure,the content of Ti4+ on the surface of the films decreases gradually.