The effect of nanocrystallite size in monoclinic HfO{sub 2} films on lattice expansion and near-edge optical absorption

Journal Article · Mon May 10 04:00:00 EDT 2010 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3428965· OSTI ID:21347439

Cisneros-Morales, M C; Aita, C R ^[1]

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1. Department of Chemistry and Biochemistry and the Advanced Coatings Experimental Laboratory, University of Wisconsin-Milwaukee, P.O. Box 413, Milwaukee, Wisconsin 53201 (United States)

Nanocrystalline monoclinic HfO{sub 2} films were sputter deposited on fused silica substrates, air annealed at 573 to 1273 K to affect crystallite growth, and analyzed by x-ray diffraction and spectrophotometry. Lattice expansion occurs with diminishing crystallite size. O 2p->Hf 5d interband absorption dominates the optical edge at energy E>=6.24 eV, with an optical band gap, E{sub o}=5.48+-0.023, which is independent of crystallite size. However, the strength of a localized resonant band, with onset at 5.65 eV and maximum at 5.94 eV, is affected by crystallite size. Its polaronic origin in a perfect HfO{sub 2} lattice is discussed.

• OSTI ID: 21347439
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 19 Vol. 96; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION
AIR
ANNEALING
CHALCOGENIDES
COHERENT SCATTERING
CRYSTAL GROWTH
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CRYSTALS
DEPOSITION
DIELECTRIC MATERIALS
DIFFRACTION
FABRICATION
FILMS
FLUIDS
GASES
HAFNIUM COMPOUNDS
HAFNIUM OXIDES
HEAT TREATMENTS
MATERIALS
MINERALS
MONOCLINIC LATTICES
NANOSTRUCTURES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SEMICONDUCTOR MATERIALS
SILICA
SORPTION
SPECTROPHOTOMETRY
SPUTTERING
SUBSTRATES
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION