| Autor: |
R. C. Blasdell, V. I. Kushnir, Albert T. Macrander, P. A. Montano, Bernard R. Cooper, C.-C. Kao, David L. Price |
| Rok vydání: |
1996 |
| Předmět: |
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| Zdroj: |
Physical review. B, Condensed matter. 54(1) |
| ISSN: |
0163-1829 |
| Popis: |
Inelastic x-ray scattering spectra were measured with incident x rays having an energy near 8 keV for a range of momentum transfers q extending from 0.70 to 2.0 \AA{} $^{\mathrm{\ensuremath{-}}1}$. We find spectral features corresponding to valence electron excitations, as well as Raman scattering corresponding to excitation from the 3p core states to the 3d valence states of Ti. The spectral features corresponding to valence electron excitations lie in the regime conventionally interpreted as a bulk plasmon together with intraband and interband transitions. We compare our data for TiC at q=1.05 \AA{} $^{\mathrm{\ensuremath{-}}1}$ with calculations for the dynamical dielectric constant \ensuremath{\varepsilon}(q,\ensuremath{\omega}) based on local-density theory. The agreement between the data and calculations permits us to interpret certain features in the spectra as arising from band transitions out of the strongly hybridized C 2p--Ti 3d band. The energy loss position of the Raman scattering peak is independent of momentum transfer for both TiC and Ti and lies at 48 eV for Ti. This value is above the highest-lying x-ray ultraviolet absorption resonance for atomic Ti at 43.5 eV. This shift in the data to higher energy transfer is consistent with electron energy loss spectra and photoemission results reported in the literature and indicates that important physical processes are not encompassed within existing theoretical approaches to x-ray Raman scattering. \textcopyright{} 1996 The American Physical Society. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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