کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5373611 | 1504225 | 2014 | 6 صفحه PDF | دانلود رایگان |
- Single site O1s, C1s and S2p double ionisation of OCS has been studied.
- The ratio between the double and single core ionisation energies are close to 2.20.
- Cross section ratios between double and single core-hole creation are extracted.
- Auger spectra reflecting the decay of the double core hole states were recorded.
- The data interpretation is supported by CASSCF and CASCI calculations.
Single site O1s, C1s and S2p double ionisation of the OCS molecule has been investigated using a magnetic bottle multi-electron coincidence time-of-flight spectrometer. Photon energies of 1300, 750 and 520Â eV, respectively, were used for the ionisation, and spectra were obtained from which the double core ionisation energies could be determined. The energies measured for 1s double ionisation are 1172Â eV (O1sâ2) and 659Â eV (C1sâ2). For the S2p double ionisation three dicationic states are expected, 3P, 1D and 1S. The ionisation energies obtained for these states are 373Â eV (3P), 380Â eV (1D) and 388Â eV (1S). The ratio between the double and single core ionisation energies are in all cases equal or close to 2.20. Auger spectra of OCS, associated with the O1sâ2, C1sâ2 and S2pâ2 dicationic states, were also recorded incorporating both electrons emitted as a result of the filling of the two core vacancies. As for other small molecules, the spectra show an atomic-like character with Auger bands located in the range 480-560Â eV for oxygen, 235-295Â eV for carbon and 100-160Â eV for sulphur. The interpretation of the spectra is supported by CASSCF and CASCI calculations. The cross section ratio between double and single core hole creation was estimated as 3.7Â ÃÂ 10â4 for oxygen at 1300Â eV, 3.7Â ÃÂ 10â4 for carbon at 750Â eV and as 2.2Â ÃÂ 10â3 for sulphur at 520Â eV.
Journal: Chemical Physics - Volume 439, 17 August 2014, Pages 111-116