Structure of Amorphous Tantalum Oxide and Titania-Doped Tantala: 17O NMR Results for Sol–Gel and Ion-Beam-Sputtered Materials
Structure of Amorphous Tantalum Oxide and Titania-Doped Tantala: 17O NMR Results for Sol–Gel and Ion-Beam-Sputtered Materials
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DOI：
10.1021/cm200630m
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发表时间：
2011-07
影响因子：
8.6
通讯作者：
Namjun Kim;J. Stebbins
中科院分区：
文献类型：
--
作者：
Namjun Kim;J. Stebbins
Amorphous thin films of high-refractive index metal oxides such as Ta2O5 are critical in multilayer optical components such as the main mirrors of the Laser Interferometer Gravitational-Wave Observatory (LIGO), but their atomic-scale structures are not well-known. Amorphous, pure, and titania-doped tantalum oxides were prepared by sol–gel synthesis and by ion-beam sputtering. The samples were successfully enriched with the nuclear magnetic resonance (NMR)-active 17O isotope by heating them in 17O2 gas, and they were studied using 17O solid-state NMR. 17O MAS NMR spectra of pure tantala show two resonances that correspond to two- and three-coordinated oxygens, allowing the average oxygen coordination numbers to be estimated from the relative peak areas. The average coordination number for oxide ions seems to increase as tantala changes from amorphous to crystalline. Titania-doped tantalas, (Ta1–xTix)2O5–x with x = 0.10, 0.25, and 0.50, were also studied. At the lower two dopant levels, Ta and Ti cations ar...
