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RESEARCH PRODUCT

<title>Local structure of Ta-Re mixed oxide thin films studied by x-ray absorption spectroscopy</title>

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Mixed Ta-Re oxide thin films were synthesized for the first time by dc magnetron co-sputtering. Local environment around tantalum and rhenium atoms was studied by the Ta and Re L3-edges x-ray absorption spectroscopy in pure Ta2O5 and mixed Ta-Re oxide thin films (Ta:Re = 50:50, 38:62, 20:80 as determined from the ratio of the Ta-to-Re absorption edges). It was found that rhenium atoms are four-fold coordinated by oxygen atoms with R(Re-O) = 1.74 ± 0.01 Å and the mean square relative displacement (MSRD) σ2 = 0.0012 ± 0.0005 Å2. In pure Ta2O5 thin film, tantalum ions are coordinated by six oxygen atoms at R(Ta-O) = 2.02 ± 0.01 Å with the MSRD σ2 = 0.010 ± 0.001 Å2. The addition of rhenium ions shortens the Ta-O distance by about 0.02 - 0.03 Å and makes the Ta-0 distances distribution slightly broader with the MSRD σ2 approximately equals 0.013 ± 0.001 Å2. The high frequency contribution in the Ta L3-edge EXAFS signals, which is responsible in its Fourier transform for the peak beyond the first coordination shell, is due to the multiple-scattering effects within distorted [TaO6] octahedron.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.