Samenvatting
Thin magnetite (Fe304) films and Fe304/MgO multilayers have been epitaxially grown
by Molecular Beam Epitaxy (MBE) on MgO(100) and MgA12O4(100) substrates. The epi
taxial growth on MgO(100) substrates, with a slightly larger bulk lattice parameter than
that of magnetite, resulted in an in-plane expansion of the magnetite lattice, accompanied
by a perpendicular compression. For films grown on MgAlsO4(100), with a smaller lattice
parameter, the substrate misfit is relaxed by the incorporation of misfit dislocations at the
interface. It is shown that the substrates have a large effect on the magnetic and electronic
properties of the films.
The characteristic Verwey transition is shifted towards lower temperatures, broadened,
and reduced in amplitude, more so for thinner films. This can not be quantitatively ex
plained by substrate induced stress alone, but is more likely due to a rigid structural coupling
between the magnetite film and the cubic lattice of the substrate. Hereby the orthorhombic
deformation accompanying the Verwey transition may be supressed.
When growing at reduced oxygen pressure, the length scale for the rigid coupling will
be reduced by the introduction of vacancies. This leads to more bulk-like resistivity and
Verwey transition characteristics, but also to deviations from stoichiometry, as suggested by
magnetization and Ferromagnetic Resonance (FMR) experiments.
Originele taal-2 | Engels |
---|---|
Titel | Epitaxial oxide thin films II : Symposium held November 26 - 30, 1995, Boston, Massachusetts |
Redacteuren | J.S. Speck, D.K. Fork |
Plaats van productie | Pittsburgh |
Uitgeverij | Materials Research Society |
Pagina's | 455-460 |
ISBN van geprinte versie | 1-558-99304-5 |
Status | Gepubliceerd - 1996 |
Evenement | 1995 MRS Fall Meeting - Boston, Verenigde Staten van Amerika Duur: 27 nov. 1995 → 1 dec. 1995 https://www.mrs.org/fall1995 |
Publicatie series
Naam | Materials Research Society Symposium Proceedings |
---|---|
Volume | 401 |
ISSN van geprinte versie | 0272-9172 |
Congres
Congres | 1995 MRS Fall Meeting |
---|---|
Land/Regio | Verenigde Staten van Amerika |
Stad | Boston |
Periode | 27/11/95 → 1/12/95 |
Ander | MRS Fall Meeting ; 1995 (Boston, Mass.) : 1995.11.27-30 |
Internet adres |