1. Significant reduction of dielectric loss of Ba0.51Sr0.34TiO3 film modified by Y/Mn alternate doping and preheating.
- Author
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Liu, Wenlong, Liao, Jiaxuan, Wang, Sizhe, Huang, Xiongfang, and Zhang, Yunfeng
- Subjects
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DIELECTRIC properties , *DOPING agents (Chemistry) , *THERMAL stability , *X-ray diffraction , *THIN films - Abstract
To achieve significant reduction of dielectric loss and enhancement of dielectric tunability for actual applications, a Ba 0.51 Sr 0.34 TiO 3 film modified by Y/Mn alternate doping (Y/Mn-BST 0.85 ) is prepared by an improved sol-gel method, where the film is composed of 12 layers, and odd number layers are preheated. For comparison, BST 0.85 , Y-BST 0.85 and Mn-BST 0.85 films are also prepared. XRD shows four films are ABO 3 cubic perovskite structures. The BST 0.85 film shows the smallest lattice parameter and donor doping because rich Ti 4+ ions enter into A sites to replace some Sr 2+ and Ba 2+ ions. Besides the donor doping, three doped BST 0.85 films exhibit slightly larger lattice parameters and acceptor doping because Y 3+ or Mn 2+ ions replace some Ti 4+ ions at A sites. The Y/Mn-BST 0.85 film shows the largest lattice parameter and the strongest crystallinity because Y-BST 0.85 layer and Mn-BST 0.85 layer match well in lattice structure. Compared to stoichiometric films, four nonstoichiometric films show markedly decreased dielectric losses. The Y/Mn-BST 0.85 film exhibits the lowest dielectric loss with 0.45 ~ 0.54% under the conditions of − 40 to 40V and 100 kHz, and 0.43 ~ 2.29% under the conditions of 10 Hz ~ 1 GHz and 0 V, thus can satisfy actual applications including tunable microwave application at high frequencies. The related mechanisms are studied by measuring leakage current density, observing AFM and analyzing XPS besides analyzing the XRD patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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