Preparation of bismuth layer-structured ferroelectric thin films by MOCVD and their characterization

Hiroshi Funakubo, Katsuyuki Ishikawa, Takayuki Watanabe, Masatoshi Mitsuya, Norimasa Nukaga

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

We have used new MOCVD source systems, Bi(CH3)3-Sr[Ta(OC2H5) 6]2-O2 and Bi(CH3)3-mixture of Sr[Ta(OC2H5)6]2 and Sr[Nb(OC2H5)6]2)-O2, for the highly reproducible preparation of SrBi2. Ta2O9(SBT) and SrBi2(Ta,Nb)2O9(SBTN) films, respectively. These materials are bismuth layer-structured ferroelectrics (BLSF). By using these systems, epitaxial SBT film was grown on an SrTiO3 single crystal, c-axis orientated SBT film was epitaxially grown on a (100)SrTiO3 substrate above 620°C, while a (116)-orientated one was grown on a (110)SrTiO3 substrate at 820°C. By using these orientated SBT films, we first observed the ferroelectric anisotropy of SBT film along the crystal axis; the (116)-orientated SBT film shows large ferroelectricity with a remanent polarization (Pr) of 11.4 μC/cm2, while the (001)-orientated one showed no ferro-electricity. The estimated Pr along the a-axis almost agreed with the calculated one from the SBT powder data, suggesting that there Is hardly any effect of strain in the film. This strain-free character is considered to be originated from the lattice displacement along the c-axis observed by TEM. Moreover, by using this MOCVD process, we obtained an SBTN film with relatively high ferroelectricity of Pr=6.1 μC/ cm2 even at the deposition temperature of 585°C on (111) orientated Pt-coated (100) Si substrate.

Original languageEnglish
Pages (from-to)193-200
Number of pages8
JournalAdvanced Functional Materials
Volume10
Issue number3-5
Publication statusPublished - Dec 1 2000
Externally publishedYes

Fingerprint

Ferroelectric thin films
Bismuth
Metallorganic chemical vapor deposition
bismuth
metalorganic chemical vapor deposition
preparation
Ferroelectricity
thin films
ferroelectricity
Ferroelectric materials
Substrates
Polarization
polarization
Remanence
Epitaxial films
Powders
Anisotropy
Single crystals
Transmission electron microscopy
Crystals

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrochemistry

Cite this

Preparation of bismuth layer-structured ferroelectric thin films by MOCVD and their characterization. / Funakubo, Hiroshi; Ishikawa, Katsuyuki; Watanabe, Takayuki; Mitsuya, Masatoshi; Nukaga, Norimasa.

In: Advanced Functional Materials, Vol. 10, No. 3-5, 01.12.2000, p. 193-200.

Research output: Contribution to journalArticle

Funakubo, Hiroshi ; Ishikawa, Katsuyuki ; Watanabe, Takayuki ; Mitsuya, Masatoshi ; Nukaga, Norimasa. / Preparation of bismuth layer-structured ferroelectric thin films by MOCVD and their characterization. In: Advanced Functional Materials. 2000 ; Vol. 10, No. 3-5. pp. 193-200.
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