µSR study of rutile TiO_2 defect structure

摘要

Muon is a lighter isotope of hydrogen and muon spin rotation (μSR) can be a powerful probe to specify the behavior and local structure of hydrogen inside materials. Recently accelerator based strong pulse muon facilities have been developed and has opened the new feasibility for μSR measurements using strong spin polarized muons with various kinetic energies. Titanium dioxide (TiO_2) 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. Recently hydrogen dissolved in TiO_2 during preparation process forms impurity states in the band gap to change electron excitation process and electron conductivity. We applied μSR measurement on the TiO_2 single crystal in order to understand the behavior and electronic properties of both defects and impurities.