Growth of ferroelectric bismuth lanthanum nickel titanate thin films by rf magnetron sputtering

Journal Article · Sun Apr 01 00:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2713352· OSTI ID:20982805

Kobune, Masafumi; Fukushima, Koji; Yamaji, Toru; Tada, Hideto; Yazawa, Tetsuo; Fujisawa, Hironori; Shimizu, Masaru; Nishihata, Yasuo; Matsumura, Daiju; Mizuki, Jun'ichiro; Yamaguchi, Hideshi; Kotaka, Yasutoshi; Honda, Koichiro ^[1]

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1. Department of Materials Science and Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2201 (Japan)

The epitaxial growth, structural properties, and ferroelectric properties of bismuth lanthanum nickel titanate (Bi{sub 1-x}La{sub x}) (Ni{sub 0.5}Ti{sub 0.5})O{sub 3} (BLNT) thin films deposited on Pt(100)/MgO(100) substrates by rf magnetron sputtering have been investigated using x-ray diffraction, transmission electron microscope, and polarization-electric field hysteresis loop measurements. The ferroelectric BLNT(00l) phase with c-axis orientation and a single-phase tetragonal perovskite structure appeared at x{>=}0.3. The tetragonality (c/a) increased significantly from 1.004 to 1.028 with increasing La content. The fabricated BLNT films of x{>=}0.3 indicated the apparent fourfold rotational symmetry observed for a MgO(202) substrate, a bottom Pt(202) electrode, and a BLNT(101) ferroelectric film, based on {phi} scan measurements. These results imply that the present La-substituted BLNT films are grown heteroepitaxially at x{>=}0.3. It was confirmed that Bi in the BLNT films is in a trivalent state at A sites in the perovskite crystal, based on x-ray anomalous diffraction measurements and x-ray absorption near edge structure spectra. The sputtering technique using compacted powder targets designed by taking the bond dissociation energy of metal oxides into account provided epitaxial perovskite-structured BLNT thin films on Pt(100)/MgO(100) substrates. It is shown that the c-axis oriented epitaxial BLNT film exhibits a hysteresis loop shape with a P{sub r} value of 12 {mu}C/cm{sup 2} that is comparable to typical high-performance Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12} (BLT) film.

• OSTI ID: 20982805
• Journal Information: Journal of Applied Physics, Vol. 101, Issue 7; Other Information: DOI: 10.1063/1.2713352; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
BISMUTH COMPOUNDS
CHEMICAL BONDS
CRYSTAL GROWTH
DEPOSITION
DISSOCIATION ENERGY
EPITAXY
FERROELECTRIC MATERIALS
HYSTERESIS
LANTHANUM COMPOUNDS
MAGNESIUM OXIDES
NICKEL COMPOUNDS
PEROVSKITE
POLARIZATION
SPUTTERING
THIN FILMS
TITANATES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY