Uniaxial dielectric anisotropy in Ba 0 . 5 Sr 0 . 5 TiO 3 films studied by evanescent - probe microscopy
نویسندگان
چکیده
The dielectric permittivity, tunability ~De/e!, and loss tangent of Ba12xSrxTiO3 ~BST! films grown by pulsed-laser deposition are studied by near-field microwave microscopy. Based on theoretical simulations, a method is developed to measure the uniaxial dielectric anisotropy, e' /e i , in BST films grown at different oxygen pressures. The measured e' /e i decreases with the film-growth oxygen pressure, consistent with the structural anisotropy. The films prepared at 50 mT, with e' 'e i , have the highest permittivity, tunability, and figure of merit. © 2001 American Institute of Physics. @DOI: 10.1063/1.1377628#
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