Local Structure Analysis of Lanthanum-Doped Strontium Titanate by Means of X-Ray Fluorescence Holography

We carried out X-ray fluorescence holography at an undulator beamline of SPring-8 to investigate the local structure around the La atoms in Sr0.95La0.05TiO3 single crystal at 297 K. The weak La Lγ1 radiation was detected separately from the radiations Ti Kα1, Ti Kα2 and Ti Kβ1. The La Lγ holograms were collected in the inverse mode at seven incident X-ray energies from 7.00 keV to 10.00 keV. By the holograms the clear atomic images of Sr(La) and Ti are reconstructed around the La atom. On the other hand, no images of the O atoms were discriminated from the intensities of artifacts. The atomic image around the La atom demonstrates that the La atoms are substituted for the Sr atoms in the cubic perovskite structure of SrTiO3.