Depth-resolved XAFS analysis of SrTiO thin film

Yoneda, Yasuhiro   ; Tanida, Hajime*; Takagaki, Masafumi*; Uruga, Tomoya*

Depth dependency of local structure of SrTiO thin film was investigated by X-ray absorption fine structure (XAFS). In epitaxial thin films, a large strain exists between substrates and grown films. The expitaxial strain is the largest in the interface and it is relaxed as parting from the substrate. The lattice parameter of the grown film changes depending on the lattice strain. We performed depth-resolved XAFS measurements on SrTiO thin film grown on LaAlO substrate. The depth-resolved XAFS can extract the local structures around the surface and inner regions separately. It was clarified that the bond distance between Sr and O changed greatly depending on the depth. On the other hand, the bond distance between Sr and Ti unchanged.