Conversion electron/He ion yield XAFS of SrTiO3 thin films

It is known that the dielectric constant of SrTiO3 thin film deposited on a thick substrate decreases with decreasing the thickness. This may be relat ed with local atomic distortion in SrTiO3 thin film. In order to detect the atomic distortion, Sr and Ti K-edge XAFS spectra were measured with a tota l-conversion electron/He ion-yield (CEY/CIY) apparatus which is easy to bui ld and to operate. We confirmed the validity of our fabricated CEY/CIY appa ratus and applied it to XAFS measurement of SrTiO3 thin films. Fourier tran sforms of XAFS at different thicknesses suggested the local distortion indu ced by the internal stress in thin films.