Nonstoichiometry of epitaxial FeTiO3+δ films

Tatsuo Fujii, Makoto Sadai, Masakazu Kayano, Makoto Nakanishi, Jun Takada

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)

Abstract

Epitaxial thin films of (001)-oriented FeTiO3+δ were prepared on α-Al2O3(001) single crystalline substrates by helicon plasma sputtering technique. The FeTiO3+δ films had large oxygen nonstoichiometry, which seriously depended on both substrate temperature and oxygen pressure during the sputtering deposition. The valence states of Fe ions in FeTiO3+δ changed monotonically from Fe2+ to Fe3+ with decreasing the substrate temperature from 900 to 400°C or with increasing the oxygen pressure from 0.9 to 1.8×10-6 Pa. The change of Fe valence states from Fe2+ to Fe3+ induced the magnetic phase transition only for the films prepared at 900°C. The films containing Fe2+ were paramagnetic while those with Fe3+ were antiferromagnetic at room temperature. The oxygen nonstoichiometry of the FeTiO3+δ films was probably produced by cation vacancies and disarrangement of Fe3+ and Ti4+ ions, which randomly occupied both interstitial and substitutional sites of the FeTiO3 related structure.

Original languageEnglish
Pages (from-to)55-60
Number of pages6
JournalMaterials Research Society Symposium - Proceedings
Volume746
DOIs
Publication statusPublished - 2002
EventMagnoelectronics and Magnetic Materials - Novel Phenomena and Advanced Characterization - Boston, MA, United States
Duration: Dec 1 2002Dec 5 2002

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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