Title :
Microscopic observation of interface structures of YBaCuO/MgO/YBaCuO double-heteroepitaxial thin films by TEM
Author :
Sakuta, K. ; Iyori, M. ; Kobayashi, T. ; Matsui, M. ; Nakajima, M.
Author_Institution :
Fac. of Eng. Sci., Osaka Univ., Japan
fDate :
3/1/1991 12:00:00 AM
Abstract :
The YBaCuO/MgO/YBaCuO double-heterostructure (DHS) was fabricated using conventional RF magnetron sputtering. The formation of (110)YBaCuO/(100)MgO/(110)YBaCuO on (110)SrTiO3 substrate, and (001)YBaCuO/(100)MgO/(100)YBaCuO and (001)YBaCuO/(100)MgO/(001)YBaCuO on (100)MgO substrate are demonstrated. According to RHEED (refraction high-energy electron diffraction) observations, each layer of the DHS was grown epitaxially. The cross-sectional TEM (transmission electron microscope) observation of the (001)YBaCuO/(100)MgO(2 nm)/(001)YBaCuO structure was carried out in order to characterize the heterostructure. The ultrathin MgO layer grew in an island shape. The MgO shape deposited on YBaCuO film is island-like because of the low absorption energy of Mg on the YBaCuO surface and/or large value of MgO/YBaCuO interface free energy. The YBaCuO atomic arrangement shape implied that the YBaCuO growth mechanism was atomic layer epitaxy
Keywords :
atomic layer epitaxial growth; barium compounds; high-temperature superconductors; interface structure; magnesium compounds; superconducting epitaxial layers; superconducting junction devices; transmission electron microscope examination of materials; yttrium compounds; MgO; RF magnetron sputtering; RHEED; SrTiO3; TEM; YBaCuO atomic arrangement shape; YBaCuO-MgO-YBaCuO; absorption energy; atomic layer epitaxy; double-heteroepitaxial thin films; high temperature superconductors; interface structures; Absorption; Atomic layer deposition; Diffraction; Epitaxial growth; Radio frequency; Shape; Sputtering; Substrates; Transmission electron microscopy; Yttrium barium copper oxide;
Journal_Title :
Magnetics, IEEE Transactions on
