Abstract
The measured optical and transport properties of singlecrystal SrTiO3 have been determined as a function of oxidation and reduction using spectroscopic ellipsometry, Hall and resistivity measurements. A decrease in the valence to conduction band transitions across the band gap, from O 2p to Ti 3d states, is observed by decreases in both the index of refraction and the extinction coefficient at the region of the band gap energy, in the ultraviolet region. This supports the model that oxygen nonstoichiometry depletes the O 2p densities of states in the top of the upper valence band, in agreement with previous photoemission studies. The degree of reduction decreases the band gap energy, calculated from the optical absorption coefficient spectra. The direct gap energy varies from 3.88 to 3.58 eV, and the indirect band gap energy ranging from 3.77 to 3.0 eV with increasing reduction. The resistivities of the samples decrease with increased reduction, yet free carrier densities are also found to decrease, suggesting an increase in electron mobility with reduction.
Funding statement: The authors would like to acknowledge M. F. Lemon for technical assistance with ellipsometry measurements and the comments and assistance of G. L. Tan with the manuscript. This work was partially supported under Department of Energy Office of Basic Energy Science DE-FG02-00Er45813, under National Science Foundation Award DMR-01062 in cooperation with European Union Contract G5RD-CT-2001-0586, and facilities use was supported by NSF MRSEC.
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© 2003 Carl Hanser Verlag, München
Articles in the same Issue
- Frontmatter
- Editorial
- Editorial
- Articles/Aufsätze
- The role of oxidation-induced cavities on the failure of the thermally grown oxide on binary β-NiAl alloys
- Phase stability of Y + Gd co-doped zirconia
- Mechanisms governing the distortion of alumina-forming alloys upon cyclic oxidation
- High-temperature oxidation of FeCrAl alloys: the effect of Mg incorporation into the alumina scale
- Nonlinear dielectric properties at oxide grain boundaries
- TEM observations of singular grain boundaries and their roughening transition in TiO2-excess BaTiO3
- Processing of dense MgO substrates for high-temperature superconductors
- Microwave-induced crystallization of polysilazane-derived silicon carbonitride
- Schottky barrier formation in liquid-phase-sintered silicon carbide
- SrTiO3: a model electroceramic
- Optical properties and electronic structure of oxidized and reduced single-crystal strontium titanate
- Spreading of liquid Ag and Ag–Mo alloys on molybdenum substrates
- Nanoalloying in mixed AgmAun nanowires
- Never ending saga of a simple boundary
- Comparison of interfacial chemistry at Cu/α-alumina and Cu/γ-alumina interfaces
- Microstructure of Cu2O/Si interfaces, made by epitaxial electrodeposition
- Metal/oxide interfaces and their reaction with hydrogen
- Amorphous films at metal/ceramic interfaces
- Some thoughts on source monochromation and the implications for electron energy loss spectroscopy
- Determination of the contrast transfer function by analysing diffractograms of thin amorphous foils
- Progress in the preparation of cross-sectional TEM specimens by ion-beam thinning
- Quantification of interfacial segregation by analytical electron microscopy
- Quantification of elemental segregation to lath and grain boundaries in low-alloy steel by STEM X-ray mapping combined with the ζ-factor method
- Microstructure of Al/Ti metallization layers
- Connectivity of CSL grain boundaries and the role of deviations from exact coincidence
- Effect of laser shock processing on the microstructure and mechanical properties of pure Cu
- Growth and microstructure of iron nitride layers and pore formation in ε-Fe3N
- Phase diagram of the Al–Cu–Fe quasicrystal-forming alloy system
- Notifications/Mitteilungen
- Personal/Personelles
- Gesellschaftsnachricht
- International Conferences
Articles in the same Issue
- Frontmatter
- Editorial
- Editorial
- Articles/Aufsätze
- The role of oxidation-induced cavities on the failure of the thermally grown oxide on binary β-NiAl alloys
- Phase stability of Y + Gd co-doped zirconia
- Mechanisms governing the distortion of alumina-forming alloys upon cyclic oxidation
- High-temperature oxidation of FeCrAl alloys: the effect of Mg incorporation into the alumina scale
- Nonlinear dielectric properties at oxide grain boundaries
- TEM observations of singular grain boundaries and their roughening transition in TiO2-excess BaTiO3
- Processing of dense MgO substrates for high-temperature superconductors
- Microwave-induced crystallization of polysilazane-derived silicon carbonitride
- Schottky barrier formation in liquid-phase-sintered silicon carbide
- SrTiO3: a model electroceramic
- Optical properties and electronic structure of oxidized and reduced single-crystal strontium titanate
- Spreading of liquid Ag and Ag–Mo alloys on molybdenum substrates
- Nanoalloying in mixed AgmAun nanowires
- Never ending saga of a simple boundary
- Comparison of interfacial chemistry at Cu/α-alumina and Cu/γ-alumina interfaces
- Microstructure of Cu2O/Si interfaces, made by epitaxial electrodeposition
- Metal/oxide interfaces and their reaction with hydrogen
- Amorphous films at metal/ceramic interfaces
- Some thoughts on source monochromation and the implications for electron energy loss spectroscopy
- Determination of the contrast transfer function by analysing diffractograms of thin amorphous foils
- Progress in the preparation of cross-sectional TEM specimens by ion-beam thinning
- Quantification of interfacial segregation by analytical electron microscopy
- Quantification of elemental segregation to lath and grain boundaries in low-alloy steel by STEM X-ray mapping combined with the ζ-factor method
- Microstructure of Al/Ti metallization layers
- Connectivity of CSL grain boundaries and the role of deviations from exact coincidence
- Effect of laser shock processing on the microstructure and mechanical properties of pure Cu
- Growth and microstructure of iron nitride layers and pore formation in ε-Fe3N
- Phase diagram of the Al–Cu–Fe quasicrystal-forming alloy system
- Notifications/Mitteilungen
- Personal/Personelles
- Gesellschaftsnachricht
- International Conferences