Accession Number : ADP014313


Title :   Nonstoichiometry of Epitaxial FeTiO(3+delta) Films


Descriptive Note : Conference paper


Corporate Author : OKAYAMA UNIV (JAPAN) DEPT OF APPLIED CHEMISTRY


Personal Author(s) : Fujii, Tatsuo ; Sadai, Makoto ; Kayano, Masakazu ; Nakanishi, Makoto ; Takada, Jun


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/p014313.pdf


Report Date : Jan 2003


Pagination or Media Count : 7


Abstract : Epitaxial thin films of (001)-oriented FeTiO(3+delta) were prepared on alpha-Al2O3(001) single crystalline substrates by helicon plasma sputtering technique. The FeTiO(3+delta) 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 FeTiO(3+delta) changed monotonically from Fe2+ to Fe3+ with decreasing the substrate temperature from 900 to 400 degrees C or with increasing the oxygen pressure from 0.9 to 1.8x10(-6) Pa. The change of Fe valence states from Fe2+ to Fe3+ induced the magnetic phase transition only for the films prepared at 900 degrees C. The films containing Fe2+ were paramagnetic while those with Fe3+ were antiterromagnetic at room temperature. The oxygen nonstoichiometry of the FeTiO(3+delta) 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.


Descriptors :   *MAGNETIC PROPERTIES , *THIN FILMS , CRYSTAL STRUCTURE , SYMPOSIA , PHASE TRANSFORMATIONS , SUBSTRATES , JAPAN , STOICHIOMETRY , FERRITES , ANTIFERROMAGNETISM , PARAMAGNETISM


Subject Categories : Electricity and Magnetism
      Electrical and Electronic Equipment
      Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE