Effects of annealing process on morphology and mechanical properties of magnetron sputtered LiCoO₂ thin films

• Main Authors: MA Yibo, CHEN Mu, YAN Yue, ZHANG Xiaofeng, LIU Weiming, LI Jiaming, ZHANG Xuan
• Format: Article
• Language: zho
• Published: Journal of Aeronautical Materials 2019-12-01
• Series: Journal of Aeronautical Materials
• Subjects: licoo₂ film; surface topography; hardness; young’s modulus; friction coefficient
• Online Access: http://jam.biam.ac.cn/CN/Y2019/V39/I6/90
• ISSN: 1005-5053; 1005-5053

LiCoO₂ thin films were prepared on single crystal Si (100) by magnetron sputtering method and then annealed by different annealing temperatures, holding times and atmospheres. The effects of annealing processes on the surface morphologies, compositions, crystal structures and mechanical properties of LiCoO₂ films were investigated. The results show that the surface average roughness of LiCoO₂ film is reduced from 11.63 nm to 6.13 nm; annealing atmosphere has the greatest influence on the surface morphologies of LiCoO₂ films. The LiCoO₂ film composition is destroyed due to Li₂O, CoO, Co₃O₄ by-products formed during annealing process. LiCoO₂ film are crystallized under any annealing conditions, the average grain size is about 30 nm, annealing temperature has the greatest influence on the grain size and residual stress. After annealing, the hardness and young's modulus of LiCoO₂ films are increased by an order of magnitude. Under the optimal annealing process (600 ℃, 60 min, pure O₂ atmosphere), the ratio of <i>H</i>³/<i>E</i>_r² is 0.03 GPa, which shows excellent resistance to plastic deformation.