TiO2薄膜的相结构调控与表征

TiO₂薄膜的相结构调控与表征

李  祥，姚婷婷，江亦潇，陈春林^*，马秀良，叶恒强

(1.中国科学院金属研究所沈阳材料科学国家研究中心，辽宁沈阳110016；2.中国科学技术大学材料科学与工程学院，辽宁沈阳110016；3.季华实验室，广东佛山528200)

摘  要本文利用脉冲激光沉积技术在LaAlO₃(001)衬底上生长了单晶锐钛矿和双相TiO₂薄膜，并利用X射线衍射和透射电子显微术对薄膜的显微结构进行了系统表征。单晶锐钛矿薄膜在LaAlO₃(001)衬底上实现了外延生长，双相TiO₂薄膜以单晶锐钛矿TiO₂为基体，在其中夹杂着金红石TiO₂颗粒。TiO₂薄膜的相结构可通过调整靶材与衬底的间距来调控，远靶基距（150 mm）利于单晶锐钛矿薄膜生长，近靶基距（50 mm）易获得双相TiO₂薄膜。锐钛矿TiO₂电镜样品在离子减薄过程中易发生表面还原，导致电镜观察中出现莫尔条纹。研究表明30% H₂O₂浸泡可有效去除离子减薄样品表面的损伤层，防止莫尔条纹的出现。

关键词  TiO₂；单晶薄膜；双相薄膜；莫尔条纹；脉冲激光沉积

中图分类号：O484.1；O785；O742⁺.4；TG115.21⁺5.3   文献标识码：A    doi:10.3969/j.issn.1000-6281.2022.02.002

Phase structure regulation and characterization of TiO₂ thin films

LI Xiang^1，2, JIANG Yi-xiao^1，3, YAO Ting-ting^1，3, CHEN Chun-lin^1，3*, MA Xiu-liang¹, YE Heng-qiang³

(1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang Liaoning 110016；2. School of Material Science and Engineering, University of Science and Technology of China, Shenyang Liaoning 110016；3. Ji Hua Laboratory, Foshan Guangdong 528200, China)

Abstract  In this paper, single-crystal anatase and dual-phase TiO₂ thin films were grown on LaAlO₃ (001) substrates by pulsed laser deposition. The microstructures of the as-prepared thin films were systematically characterized by X-ray diffraction and transmission electron microscopy.Single-crystal anatase thin films were epitaxially grown on LaAlO₃ (001) substrates, and dual-phase TiO₂ thin films were composed of the single-crystal anatase TiO₂ matrix and numerous embedded rutile particles. The phase structure of the TiO₂ thin films can be adjusted by changing the target-substrate distance. The long target-substrate distance (150 mm) is conducive to the growth of single-crystal anatase films, while the short target-substrate distance (50 mm) promotes the formation of dual-phase TiO₂ films. TEM samples of anatase TiO₂ are prone to surface reduction during the ion thinning process, resulting in the appearance of moiré fringes in TEM observations. It is revealed that 30% H₂O₂ immersion can effectively remove the damage layer on the surface of the ion-thinned sample and prevent the appearance of moiré fringes.

Keyword  TiO₂；single-crystal thin film；dual-phase thin film；Moiré fringes；pulsed laser deposition

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