Dielectric Enhancement in Graphene/Barium Titanate Nanocomposites

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• 作者：Bingcheng Luo ; Xiaohui Wang ; Enke Tian ; Huiling Gong ; Qiancheng Zhao ; Zhengbo Shen ; Yan Xu ; Xiaoyue Xiao ; Longtu Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：February 10, 2016
• 年：2016
• 卷：8
• 期：5
• 页码：3340-3348
• 全文大小：676K
• ISSN：1944-8252

文摘

GN/BT nanocomposites were fabricated via colloidal processing methods, and ceramics were sintered through two-step sintering methods. The microstructure and morphology were characterized by X-ray diffraction, high-resolution transmission electron microscopy, and field emission scanning electron microscopy. XRD analysis shows that all samples are perovskite phases, and the lattice parameters a and c almost decrease linearly with the increase of graphene nanosheets. The dielectric properties were tested by using precision impedance. The maximum dielectric constant at the Curie temperature for the nanocomposites with graphene addition of 3 wt % is about 16?000, almost 2 times more than that of pure BaTiO₃ ceramics. The relaxation, band structure, density of states, and charge density distribution of GN/BT superlattices were calculated using first-principles calculations for the first time, and results showed the strong hybrid interactions between C 2p states and O 2p and Ti 3d orbitals.