Phase transitions in LiCoO2 thin films prepared by pulsed laser deposition
Phase transitions in LiCoO2 thin films prepared by pulsed laser deposition
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脉冲激光沉积制备 LiCoO2 薄膜的相变
DOI：
10.1016/j.matchemphys.2012.02.022
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发表时间：
2012-04
影响因子：
4.6
通讯作者：
Ikuhara, Yuichi
中科院分区：
文献类型：
--
作者：
Huang, Rong;Hitosugi, Taro;Fisher, Craig A. J.;Ikuhara, Yumi H.;Moriwake, Hiroki;Oki, Hideki;Ikuhara, Yuichi
采用选区电子衍射、高分辨透射电子显微镜、球差校正的高角度环形暗场扫描透射电子显微镜、透射电子显微镜和透射电子显微镜等分析手段，研究了室温下脉冲激光沉积在蓝宝石（α-Al 2 O3）衬底（0001）面上外延生长的LiCoO 2薄膜的微观结构，和电子能量损失光谱学。沉积态LiCoO 2薄膜由具有立方岩盐结构的完全无序相（γ）的外延晶粒组成。在退火过程中，这种具有双晶结构的相转变为完全有序的三角（α）相，其基面平行于蓝宝石衬底表面。虽然整体的薄膜似乎是一个单晶，少量的Co 3 O 4晶粒也观察到退火薄膜，表明一些锂和O在加工过程中损失。薄膜和衬底之间的原子级尖锐界面在退火过程中也变得粗糙，形成台阶缺陷，表明在界面处发生了局部反应。
Microstructures of epitaxial LiCoO2thin films formed on the (0001) surface of sapphire (α-Al2O3) substrates by pulsed laser deposition at room temperature and annealed at 600°C in air were investigated by a combination of selected-area electron diffraction, high-resolution transmission electron microscopy, spherical-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, and electron energy-loss spectroscopy. As-deposited LiCoO2thin films consisted of epitaxial grains of the fully cation-disordered phase (γ) with a cubic rock-salt structure. During annealing, this cubic-structured phase transformed into the fully ordered trigonal (α) phase oriented with its basal plane parallel to the surface of the sapphire substrate. Although overall the film appeared to be a single crystal, a small number of Co3O4grains were also observed in annealed thin films, indicating that some Li and O had been lost during processing. The atomically sharp interface between the film and substrate also became rougher during annealing, with step defects being formed, suggesting that a localized reaction occurred at the interface.
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影响因子：
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作者：
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影响因子：
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作者：
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影响因子：
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作者：
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作者：
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影响因子：
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