[1Cp01-13] SS3

[1Cp09] Structural analysis of defect structure in rutile TiO₂ by µSR method

*hiroko miwa¹, Koichiro Shimomura², Amba Datt Pant², Eiko Torikai³, Kanetada Nagamine^2,4, Kiyotaka Asakura⁵ (1. The University of Electro-Communications, 2. High Energy Accelerator Research Organization, 3. University of Yamanashi, 4. University of California, 5. Institute for Catalysis, Hokkaido University)

Muon, which has a spin 1/2, finite life time to eject positron in the spin direction and about 1/9 weight of the proton, can be used as a probe to specify the behavior and local structure of hydrogen inside materials. The methodology is called as muon spin rotation/relaxation (μSR) spectroscopy. Recently accelerator based strong pulse muon facilities have been developed and has opened the new feasibility for μSR measurements. TiO₂ is the most widely used material as high efficiency photocatalysis. One of the crucial and unrevealed issues are properties of defects, e.g. oxygen vacancies, hydrogen. Recently hydrogen dissolved in TiO₂ during preparation process forms impurity states in the band gap to change electron excitation process and electron conductivity. We applied μSR measurement on the TiO₂ single crystal in order to understand the behavior and electronic properties of both defects and impurities. In this contribution we will show the muon interaction with oxygen vacancy of TiO₂ by zero-field, longitudinal and transverse external field μSR spectra. Those results show stable sites of muon (hydrogen) and electron distribution in the reduced TiO₂.