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

抄録

We carried out X-ray fluorescence holography at an undulator beamline of SPring-8 to investigate the local structure around the La atoms in Sr_0.95La_0.05TiO₃ 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.