Characterization of bicrystalline epitaxial LaNiO3 films fabricated on MgO (1 0 0) substrates by pulsed laser deposition

• Published in: Applied surface science Vol. 252; no. 10; pp. 3609 - 3615
• Main Authors: Zheng, Liang, Zhu, Jun, Zhang, Ying, Jiang, Shu Wen, Li, Yan Rong, HuaWei, Xian, Li, Jin Long
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Science 15.03.2006
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Physics; Inorganic compounds; Epitaxial layers; Epitaxy; X-ray diffraction; Pulsed laser deposition; XRD; Film growth; Bicrystalline epitaxy; MgO; Magnesium oxides; LaNiO3; Pole figures; Pole figure
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2005.05.044

A series of metallic LaNiO3 (LNO) thin films were deposited on MgO (100) substrates by pulsed laser deposition (PLD) under the oxygen pressure of 20Pa at different substrate temperatures from 450 to 750 deg C. X-ray diffraction (XRD) was used to characterize the crystal structure of LNO films. theta-2theta scans of XRD indicate that LNO film deposited at a substrate temperature of 700 deg C has a high orientation of (ll0). At other substrate temperatures, the LNO films have mixed phases of (ll0) and (l00). Furthermore, pole figure measurements show that LNO thin films, with the bicrystalline structure, were epitaxially deposited on MgO (100) substrates in the mode of LNO (110)//MgO (100) at 700 deg C. Reflection high-energy electric diffraction (RHEED) and atomic force microscopy (AFM) were also performed to investigate the microstructure of LNO films with the high (ll0) orientation. RHEED patterns clearly confirm this epitaxial relationship. An atomically smooth surface of LNO films at 700 deg C was obtained. In addition, bicrystalline epitaxial LNO films, fabricated at 700 deg C, present a excellent conductivity with a lower electrical resistivity of 300muOmegacm. Thus, the obtained results indicate that bicystalline epitaxial LNO films could serve as a promising candidate of electrode materials for the fabrication of ferroelectric or dielectric films.