Preparation of TaO2 thin films using NbO2 template layers by a pulsed laser deposition technique

THIN SOLID FILMS

卷:599

Article

Muraoka, Y.^1,2  Fujimoto, Y.¹  Kameoka, M.²  Matsuura, Y.²  Sunagawa, M.¹  Terashima, K.^1,2  Wakita, T.^1,2  Yokoya, T.^1,2 

[1] Okayama Univ, Grad Sch Nat Sci & Technol, Okayama 7008530, Japan

[2] Okayama Univ, Surface Sci Res Lab, Fac Sci, Okayama 7008530, Japan

关键词: Tantalum dioxide;    Thin film;    Niobium dioxide;    Template layer;    Pulsed laser deposition;    Epitaxy;    X-ray photoelectron spectroscopy;   

DOI  :  10.1016/j.tsf.2015.12.066

来源: Elsevier

【 摘 要 】

TaO2 thin films were prepared using rutile-type NbO2 template layers on Al2O3 (0001) substrates by a pulsed laser deposition technique. The structural and electronic properties of the films were characterized by performing four-circle X-ray diffraction (XRD) and X-ray photoemission spectroscopy (XPS) measurements. Four-circle XRD measurements revealed the formation and epitaxial growth of (100)-oriented tetragonal TaO2 on the NbO2 template layers. On the other hand, XPS measurements showed two kinds of valence states, namely Ta4+ and Ta5+ in the surface region of the film. The results from the XRD and XPS measurements suggest that the film is composed of epitaxially grown TaO2 with an amorphous Ta2O5 surface layer. It is found from control experiments that the NbO2 template layers play an important role in inducing the crystallization of the TaO2 films and promoting the formation of Ta4+ in the films deposited thereon. The results indicate the effectiveness of the NbO2 template layers for the formation of TaO2 thin films. Our work presents a promising method for the preparation of TaO2 thin films and provides a starting point for further research on TaO2. (C) 2015 Elsevier B.V. All rights reserved.

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