Oxygen off-stoichiometry and phase separation in EuO thin films

Journal Article · Sat Oct 15 00:00:00 EDT 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.84.155442· OSTI ID:21596904

Altendorf, S G; Efimenko, A; Oliana, V ^[1]; Kierspel, H ^[1]; Rata, A D; Tjeng, L H ^[2]

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1. II. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, DE-50937 Koeln (Germany)
2. Max Planck Institute for Chemical Physics of Solids, Noethnitzerstr. 40, DE-01187 Dresden (Germany)

We report on our study on the influence of the growth conditions on the europium/oxygen stoichiometry, morphology, magnetic properties, and electrical conductivity of EuO thin films. SQUID magnetometry and x-ray photoelectron spectroscopy were utilized as complementary techniques to determine the oxygen content of EuO{sub 1{+-}x} thin films grown by molecular beam epitaxy with and without the employment of the so-called Eu distillation process. We found indications for phase separation to occur in Eu-rich as well as in over-oxidized EuO for films grown at substrate temperatures below the Eu distillation temperature. Only a fraction of the excess Eu contributes to the metal-insulator transition in Eu-rich films grown under these conditions. We also observed that the surfaces of these films were ill defined and may even contain more Eu excess than the film average. Only EuO films grown under distillation conditions are guaranteed to have the same magnetic and electrical properties as stoichiometric bulk EuO, and to have surfaces with the proper Eu/O stoichiometry and electronic structure.

• OSTI ID: 21596904
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 84, Issue 15; Other Information: DOI: 10.1103/PhysRevB.84.155442; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DISTILLATION
ELECTRIC CONDUCTIVITY
ELECTRONIC STRUCTURE
EUROPIUM
EUROPIUM OXIDES
MAGNETIC PROPERTIES
MOLECULAR BEAM EPITAXY
OXYGEN
SQUID DEVICES
STOICHIOMETRY
SUBSTRATES
SURFACES
THIN FILMS
X-RAY PHOTOELECTRON SPECTROSCOPY
CHALCOGENIDES
CRYSTAL GROWTH METHODS
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ELECTRONIC EQUIPMENT
ELEMENTS
EPITAXY
EQUIPMENT
EUROPIUM COMPOUNDS
FILMS
FLUXMETERS
MEASURING INSTRUMENTS
METALS
MICROWAVE EQUIPMENT
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
RARE EARTHS
SEPARATION PROCESSES
SPECTROSCOPY
SUPERCONDUCTING DEVICES