X-Ray Absorption Studies of Titanium Silicide Formation at the Interface of Ti Deposited on Si

1989 ◽  
Vol 159 ◽  
Author(s):  
D.B. Aldrich ◽  
R.W. Fiordalice ◽  
H. Jeon ◽  
Q. Islam ◽  
R.J. Nemanich ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Film Structure ◽  
Titanium Silicide ◽  
Vacuum Furnace ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Absorption Studies ◽  
Metallic Bonding ◽  
X Ray Absorption

ABSTRACTNear edge X-ray absorption spectra (XANES) have been obtained from the Ti K-edge for several series of titanium silicide samples produced by different techniques. Samples were fabricated by depositing Ti on silicon wafers and subsequently annealing them up to temperatures from 100°C to 900°C in UHV, vacuum furnace, or in a Rapid Thermal Annealing system. Measurements were done in the fluorescence and total electron yield modes. The XANES measurements were correlated with Raman scattering measurements. The XANES data of several reference compounds were obtained, and the data showed a high sensitivity to changes in the film structure. Ti metallic bonding and Ti-Si bonds can be distinguished and their evolution as a function of annealing is related to previous results. For the samples with increased impurities, Ti regions were stable at higher temperatures. The XANES spectra of samples annealed under N2 indicate the formation of a surface nitride.

Short Range Order Structure Around Oxygen Atoms in the Superconductor Y-Ba-Cu-O

1987 ◽  
Vol 99 ◽  
Author(s):  
S. C. Woronick ◽  
W. Ng ◽  
A. Krol ◽  
B. X. Yang ◽  
Y. H. Kao ◽  
...  
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Local Environment ◽  
Order Structure ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Superconducting Compound ◽  
X Ray Absorption ◽  
Oxygen Atoms

ABSTRACTSpectra of the oxygen K-edge extended x-ray absorption fine structure (EXAFS) of the superconducting compound Y-Ba-Cu-O were obtained by measuring the total electron yield as a function of incident x-ray energy at temperatures between 77K and 300K. This technique affords a convenient way for probing the local environment around the oxygen atoms and soft modes in the lattice.

VUV- and Soft X-Ray-Induced Optical Luminescence and X-Ray Absorption Fine Structures of Porous Silicon

1992 ◽  
Vol 281 ◽  
Author(s):  
T. K. Sham ◽  
D. T. Jiang ◽  
I. Coulthard ◽  
J. W. Lorimer ◽  
X. H. Feng ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Absorption Fine ◽  
Electron Yield ◽  
Optical Luminescence ◽  
Fine Structures ◽  
X Ray Absorption ◽  
Uv Excitation

ABSTRACTOptical luminescence in porous silicon induced by soft X-ray and vacuum UV excitation with energies in the vicinity of the Si K-edge (1838 eV) and the Si L-edge (99 eV) has been observed. The luminescence has been used, together with total electron yield, to record X-ray absorption fine structure (XAFS) in the near-edge region of both Si edges. The near- edge spectra recorded simultaneously with either luminescence or total electron yield were compared, and the implications of these measurements for the structure of porous silicon are discussed.

Characterization of Ce-Doped LaPO4 by X-Ray Absorption Spectroscopy

1993 ◽  
Vol 329 ◽  
Author(s):  
D. K. Shuh ◽  
L. J. Terminello ◽  
L. A. Boatner ◽  
M. M. Abraham ◽  
D. Perry
Keyword(s):  
Absorption Spectroscopy ◽  
Full Width Half Maximum ◽  
Energy Shift ◽  
Total Electron Yield ◽  
Total Electron ◽  
X Ray ◽  
Trivalent State ◽  
Radiation Laboratory ◽  
X Ray Absorption

AbstractX-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d104fn→3d94fn+1 (M4,5) transitions that contain a wealth of spectroscopic features. XAS is a useful technique for the characterization of 4f-occupancy, 4f-hybridization, and valence in RE-containing materials. The XAS measurements of the single crystal RE-orthophosphates, as well as a range of Ce- doped (˜l–30%) LaPO4 hosts were performed at the 3d edge in the total electron yield mode at beamline 8–2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble that of the corresponding RE metal and emphasize the major contribution of the trivalent state to the electronic transitions occurring at the 3d edge. There is no energy shift of the La and Ce absorption peaks with Ce doping and furthermore, no additional transitions are observed in either spectral region. However, accompanying the Ce doping there is a significant narrowing of the La absorption peak full width half maximum that contrasts to the Ce features that exhibit no contraction. The La and Ce spectra indicate that the Ce-doping of LaPO4 is purely substitutional.

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