X-ray standing wave and ion scattering studies on Au-implanted LiNbO3(0001) single crystals

X-ray standing wave and combined Rutherford backscattering spectrometry and channeling experiments have been performed on Au-implanted and annealed (0001)-oriented LiNbO3 single crystals. At an ion dose of ⋍ 1 × 1015 cm−2 confined in a 117 nm thick (FWHM) layer, resulting in a View the MathML source ratio of ≅ 5 × 10−3, no significant cluster formation has been observed. Most of the Au atoms have been found to lie on the c-axis of the LiNbO3 structure. However, they do not occupy a single lattice site. Rather they appear to be distributed over several sites on the [0001] atomic strings, which contain Nb, Li and structural vacancy sites. A small fraction (∼ ca. 20%) of the Au atoms appear to be displaced from the threefold symmetry axis - most likely at tetrahedral sites. The possibility of this fraction of Au atoms existing as small clusters like dimers or trimers cannot be ruled out.