Abstract
Time-resolved hard x-ray photoelectron spectroscopy (trHAXPES) is established using the x-ray free-electron laser SACLA. The technique extends time-resolved photoemission into the hard x-ray regime and, as a core-level spectroscopy, combines element and atomic-site specificity and sensitivity to the chemical environment with femtosecond time resolution and bulk (sub-surface) sensitivity. The viability of trHAXPES using 8 keV x-ray free-electron-laser radiation is demonstrated by a systematic investigation of probe and pump pulse-induced vacuum space-charge effects on the V 1s emission of VO2 and the Ti 1s emission of SrTiO3. The time and excitation energy dependencies of the measured spectral shifts and broadenings are compared to the results of N-body numerical simulations and simple analytic (mean-field) models. Good agreement between the experimental and calculated results is obtained. In particular, the characteristic temporal evolution of the pump pulse-induced spectral shift is shown to provide an effective means to determine the temporal overlap of pump and probe pulses. trHAXPES opens a new avenue in the study of ultrafast atomic-site specific electron and chemical dynamics in materials and at buried interfaces.
| Original language | English |
|---|---|
| Article number | 123045 |
| Journal | New Journal of Physics |
| Volume | 16 |
| DOIs | |
| Publication status | Published - Dec 17 2014 |
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Keywords
- space-charge effects
- time-resolved photoelectron spectroscopy
- x-ray free-electron laser
ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Time-resolved HAXPES at SACLA : Probe and pump pulse-induced space-charge effects. / Oloff, L. P.; Oura, M.; Rossnagel, K.; Chainani, A.; Matsunami, M.; Eguchi, Ritsuko; Kiss, T.; Nakatani, Y.; Yamaguchi, T.; Miyawaki, J.; Taguchi, M.; Yamagami, K.; Togashi, T.; Katayama, T.; Ogawa, K.; Yabashi, M.; Ishikawa, T.
In: New Journal of Physics, Vol. 16, 123045, 17.12.2014.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Time-resolved HAXPES at SACLA
T2 - Probe and pump pulse-induced space-charge effects
AU - Oloff, L. P.
AU - Oura, M.
AU - Rossnagel, K.
AU - Chainani, A.
AU - Matsunami, M.
AU - Eguchi, Ritsuko
AU - Kiss, T.
AU - Nakatani, Y.
AU - Yamaguchi, T.
AU - Miyawaki, J.
AU - Taguchi, M.
AU - Yamagami, K.
AU - Togashi, T.
AU - Katayama, T.
AU - Ogawa, K.
AU - Yabashi, M.
AU - Ishikawa, T.
PY - 2014/12/17
Y1 - 2014/12/17
N2 - Time-resolved hard x-ray photoelectron spectroscopy (trHAXPES) is established using the x-ray free-electron laser SACLA. The technique extends time-resolved photoemission into the hard x-ray regime and, as a core-level spectroscopy, combines element and atomic-site specificity and sensitivity to the chemical environment with femtosecond time resolution and bulk (sub-surface) sensitivity. The viability of trHAXPES using 8 keV x-ray free-electron-laser radiation is demonstrated by a systematic investigation of probe and pump pulse-induced vacuum space-charge effects on the V 1s emission of VO2 and the Ti 1s emission of SrTiO3. The time and excitation energy dependencies of the measured spectral shifts and broadenings are compared to the results of N-body numerical simulations and simple analytic (mean-field) models. Good agreement between the experimental and calculated results is obtained. In particular, the characteristic temporal evolution of the pump pulse-induced spectral shift is shown to provide an effective means to determine the temporal overlap of pump and probe pulses. trHAXPES opens a new avenue in the study of ultrafast atomic-site specific electron and chemical dynamics in materials and at buried interfaces.
AB - Time-resolved hard x-ray photoelectron spectroscopy (trHAXPES) is established using the x-ray free-electron laser SACLA. The technique extends time-resolved photoemission into the hard x-ray regime and, as a core-level spectroscopy, combines element and atomic-site specificity and sensitivity to the chemical environment with femtosecond time resolution and bulk (sub-surface) sensitivity. The viability of trHAXPES using 8 keV x-ray free-electron-laser radiation is demonstrated by a systematic investigation of probe and pump pulse-induced vacuum space-charge effects on the V 1s emission of VO2 and the Ti 1s emission of SrTiO3. The time and excitation energy dependencies of the measured spectral shifts and broadenings are compared to the results of N-body numerical simulations and simple analytic (mean-field) models. Good agreement between the experimental and calculated results is obtained. In particular, the characteristic temporal evolution of the pump pulse-induced spectral shift is shown to provide an effective means to determine the temporal overlap of pump and probe pulses. trHAXPES opens a new avenue in the study of ultrafast atomic-site specific electron and chemical dynamics in materials and at buried interfaces.
KW - space-charge effects
KW - time-resolved photoelectron spectroscopy
KW - x-ray free-electron laser
UR - http://www.scopus.com/inward/record.url?scp=84927127456&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84927127456&partnerID=8YFLogxK
U2 - 10.1088/1367-2630/16/12/123045
DO - 10.1088/1367-2630/16/12/123045
M3 - Article
AN - SCOPUS:84927127456
VL - 16
JO - New Journal of Physics
JF - New Journal of Physics
SN - 1367-2630
M1 - 123045
ER -