IN-SITU GROWTH OF LAYERED, SPINEL, AND ROCK-SALT LICOO2 BY LASER-ABLATION DEPOSITION
IN-SITU GROWTH OF LAYERED, SPINEL, AND ROCK-SALT LICOO2 BY LASER-ABLATION DEPOSITION
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DOI：
10.1063/1.357514
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发表时间：
1994-09-01
影响因子：
3.2
通讯作者：
DAHN, JR
中科院分区：
文献类型：
--
作者：
ANTAYA, M;CEARNS, K;DAHN, JR
报道了在氧气背景下，通过激光烧蚀沉积在加热的衬底上原位生长三种不同相的LiCoO 2的研究。薄膜的特征在于从其中获得的晶体结构，晶体取向，晶格常数和相位信息的X射线衍射。使用电子显微镜来研究晶粒尺寸和整体膜形态。对于在2000 mTorr O2下的沉积，22-250 ℃的衬底温度产生岩盐结构，300-450 ℃产生改性尖晶石结构（低温LiCoO 2），680 ℃产生六方层状结构（高温LiCoO 2）。在500和550 ℃下生长产生了混合相尖晶石和层状LiCoO 2;然而，在550 ℃下，将O2压力降低到100 mTorr导致单相高温LiCoO 2。在岩盐相的情况下，也通过使用相同组成的烧蚀靶并在150 ℃下在200 mTorr O2下生长来产生组成Li0.5Co1.5O2和Li0.75Co1.25O2的经修改的膜化学计量。发现所有薄膜的平均晶粒尺寸随生长温度的升高而增大。通过加热使岩盐膜中的阳离子有序化是不成功的。
A study is reported of the in situ growth of three distinct phases of LiCoO2 by laser ablation deposition on heated substrates in an oxygen background. Films were characterized by x-ray diffraction from which crystal structure, crystal orientation, lattice constants, and phase information were obtained. Electron microscopy was used to investigate crystal grain size and overall film morphology. For deposition under 2000 mTorr O2, substrate temperatures of 22-250-degrees-C resulted in a rock-salt structure, 300-450-degrees-C produced a modified spinel structure (low-temperature LiCoO2), and 680-degrees-C gave a hexagonal layered structure (high-temperature LiCoO2). Growth at 500 and 550-degrees-C produced mixed-phase spinel and layered LiCoO2; however, at 550-degrees-C, reducing the O2 pressure to 100 mTorr resulted in single-phase high-temperature LiCoO2. In the case of the rock-salt phase, modified film stoichiometries of composition Li0.5Co1.5O2 and Li0.75Co1.25O2 were also produced by using ablation targets of the same composition and growing at 150-degrees-C under 200 mTorr O2. Average crystal grain size for all films was found to increase with growth temperature. Ordering of the cations in rock-salt films by heating was unsuccessful.