Title: Dielectric enhancement of Ba_0.7Sr_0.3TiO₃/Ba_0.5Sr_0.5TiO₃ multilayered thin films fabricated by chemical solution deposition

Authors: Qing Chang; Jianming Dai; Xuebin Zhu; Dajun Wu; Weijie Zhang; Yuping Sun

Addresses: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. ' Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. ' Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. ' Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. ' Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China. ' Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China; High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei 230031, China

Abstract: Multilayered Ba_0.7Sr_0.3TiO₃/Ba_0.5Sr_0.5TiO₃ thin films with different deposition sequences were deposited on Pt/Ti/SiO₂/Si substrates by chemical solution deposition method. Obvious dielectric enhancement occurred in Ba_0.7Sr_0.3TiO₃/Ba_0.5Sr_0.5TiO₃ multilayered thin films due to Maxwell-Wagner affect, but not happened in Ba_0.5Sr_0.5TiO₃/Ba_0.7Sr_0.3TiO₃ multilayered thin films because of the different interface quality caused by different deposition sequences. The dielectric constant and tunability of Ba_0.7Sr_0.3TiO₃/Ba_0.5Sr_0.5TiO₃ multilayered thin films at 200 kHz (590 and 46%, respectively) were higher than that of Ba_0.7Sr_0.3TiO₃ and Ba_0.5Sr_0.5TiO₃ monolayer thin films (470, 32% and 430, 29%, respectively). Besides, the dielectric loss tangent of Ba_0.7Sr_0.3TiO₃/Ba_0.5Sr_0.5TiO₃ multilayered thin films (0.025) was lower than that of Ba_0.7Sr_0.3TiO₃ and Ba_0.5Sr_0.5TiO₃ monolayer thin films (0.033, 0.052, respectively). Comparing with that of Ba_0.7Sr_0.3TiO₃ and Ba_0.5Sr_0.5TiO₃ monolayer thin films, the dielectric properties of Ba_0.7Sr_0.3TiO₃/Ba_0.5Sr_0.5TiO₃ multilayered thin films had certain of improvement, which is of benefit to applications in tunable microwave devices.

Keywords: barium strontium titanate; BST; chemical solution deposition; CSD; multilayered thin films; dielectric enhancement; tunable microwave devices.

DOI: 10.1504/IJNP.2012.044498

International Journal of Nanoparticles, 2012 Vol.5 No.1, pp.64 - 72

Received: 16 Apr 2011
Accepted: 10 May 2011
Published online: 20 Aug 2014 *

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