Postdeposition annealing induced transition from hexagonal Pr{sub 2}O{sub 3} to cubic PrO{sub 2} films on Si(111)

Journal Article · Mon Jun 15 04:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3152796· OSTI ID:21352264

Weisemoeller, T; Bertram, F; Gevers, S; Greuling, A; Deiter, C; Tobergte, H; Neumann, M; Wollschlaeger, J ^[1]; Giussani, A; Schroeder, T ^[2]

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1. Fachbereich Physik, Universitaet Osnabrueck, D-49076 Osnabrueck (Germany) and Center of Interface Science, Barbarastrasse 7, D-49069 Osnabrueck (Germany)
2. IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany)

Films of hexagonal praseodymium sesquioxide (h-Pr{sub 2}O{sub 3}) were deposited on Si(111) by molecular beam epitaxy and thereafter annealed in 1 atm oxygen at different temperatures, ranging from 100 to 700 deg. C. The films of the samples annealed at 300 deg. C or more were transformed to PrO{sub 2} with B-oriented Fm3m structure, while films annealed at lower temperatures kept the hexagonal structure. The films are composed of PrO{sub 2} and PrO{sub 2-d}elta species, which coexist laterally and are tetragonally distorted due to the interaction at the interface between oxide film and Si substrate. Compared to PrO{sub 2}, PrO{sub 2-d}elta has the same cubic structure but with oxygen vacancies. The oxygen vacancies are partly ordered and increase the vertical lattice constant of the film, whereas the lateral lattice constant is almost identical for both species and on all samples. The latter lattice constant matches the lattice constant of the originally crystallized hexagonal praseodymium sesquioxide. That means that no long range reordering of the praseodymium atoms takes place during the phase transformation.

• OSTI ID: 21352264
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 105; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL GROWTH
CRYSTAL GROWTH METHODS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
ELEMENTS
EPITAXY
FCC LATTICES
FILMS
HEAT TREATMENTS
LATTICE PARAMETERS
MATERIALS
METALS
MOLECULAR BEAM EPITAXY
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POINT DEFECTS
PRASEODYMIUM
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RARE EARTH COMPOUNDS
RARE EARTHS
SEMICONDUCTOR MATERIALS
SEMIMETALS
SILICON
SUBSTRATES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THIN FILMS
VACANCIES