Chemical solution deposited silver tantalate niobate, Ag x (Ta0.5Nb0.5)O3-y , thin films on (111)Pt/Ti/SiO2/(100)Si substrates
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2007
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Abstract
Silver tantalate niobate films are candidates for temperature stable microwave dielectrics. In this work, a chemical solution deposition synthesis method was developed for Ag x (Ta0.5Nb0.5) O3-y films on Pt-coated Si substrates. Stable solutions with a range of silver stoichiometries were prepared using 2-methoxyethanol and pyridine as solvents, from AgNO3 and Nb and Ta ethoxide precursors. It was extremely difficult to prepare phase-pure perovskite films of Ag(Ta 0.5Nb0.5)O3 on Pt-coated Si subtrates; instead a mixture of perovskite and natrotantite phases was identified. Such mixed phase films had dielectric constant r and dielectric loss tanδ values ranging from 200±20 to 270±25 and 0.006±0.002 to 0.002±0.001 at 100kHz, respectively, depending on the firing temperature. For Ag2(Ta0.5Nb0.5)4O11, Ag0.8(Ta0.5Nb0.5)O2.9, Ag 0.85(Ta0.5Nb0.5)O2.925 and Ag 0.9(Ta0.5Nb0.5)O2.95 films, mainly the natrotantite phase was observed. The r values of these films were between 70±10 and 130±15 with tan δ values of 0.008±0.002 at 100 kHz. © Springer Science + Business Media, LLC 2007.