Electron band structure of C_(60) single crystal has been investigated using synchrotron radiation.On the cleaved(111)surface of the C_(60) single crystal the angle-resolved ultraviolet photoelectron spectra were meas...Electron band structure of C_(60) single crystal has been investigated using synchrotron radiation.On the cleaved(111)surface of the C_(60) single crystal the angle-resolved ultraviolet photoelectron spectra were measured at normal emission with varying photon energy from 12.7 to 28.2eV.The valence band dispersions in L-r-L direction were successfully observed.The dispersions are 0.14 and 0.17eV for the highest occupied molecular orbitals(HOMO)and HOMO-1 derived band respectively.展开更多
Small Angle X-ray Scattering (SAXS) experiment using Synchrotron Radiation as X-ray source was used to determine the average wall thickness of mesoporous silica prepared by condensation of tetraethylorthosilicate (TEO...Small Angle X-ray Scattering (SAXS) experiment using Synchrotron Radiation as X-ray source was used to determine the average wall thickness of mesoporous silica prepared by condensation of tetraethylorthosilicate (TEOS) using non-ionic alkylpolyethyleneoxide (AEO(9)) surfactant as templates. The results agreed with that of high-resolution TEM (HRTEM) measurement.展开更多
For submonolayer amounts of C_(60)condensed on Sn substrate,the peaks derived from top two occupied molecular orbitals were broadened by 0.3eV in comparison with solid C_(60).For coverageθ<1 monolayer,the broadeni...For submonolayer amounts of C_(60)condensed on Sn substrate,the peaks derived from top two occupied molecular orbitals were broadened by 0.3eV in comparison with solid C_(60).For coverageθ<1 monolayer,the broadenings are independent of the coverage.It indicates that the delocalizations of electrons in valence bands of C_(60)are weak and the widths do not reflect the true band dispersions.展开更多
K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K....K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K. Up to four subpeaks of LUMO-derived band were observed. These sub-peaks exhibit distinct energy dispersions which resemble in general the theoretical ones calculated for K3C60 at low temperature with the so-called one-dimensional disordered structure. But there is large deviation of experimental sub-band intervals from the theoretical values. This result is meaningful for the studies of the physical properties of alkali-doped C60 solids, e.g. the mechanism for superconductivity.展开更多
The synchrotron radiation angle-resolved photoemission data of K3C60 single crystal film are analyzed, aiming at the photoionization cross-sections of the LUMO, HOMO and HOMO-1 bands in low photon energy region （14.5...The synchrotron radiation angle-resolved photoemission data of K3C60 single crystal film are analyzed, aiming at the photoionization cross-sections of the LUMO, HOMO and HOMO-1 bands in low photon energy region （14.5--27.5 eV）. Many fine structures of the HOMO/HOMO-1 intensity ratios are observed, which support the general validity of a quantum chemistry model. However, the experimental data and the theoretical results have some disagreement in the energy positions and magnitudes of the fine structures, and the disagreement is more outstanding than the case of pure C60. So the photoemission data of K3C60 afford valuable experimental reference to further theoretical developments. The LUMO cross-section data, which cannot be discussed with the quantum chemistry description due to strong solid state effects, are also reported for further studies.展开更多
We have measured the synchrotron radiation photoelectron spectra of monolayer C60on Ag（100）, By calculating the intensity ratios between the LUMO bands and the two deeper bands （HOMO and HOMO- 1）, we estimate the ...We have measured the synchrotron radiation photoelectron spectra of monolayer C60on Ag（100）, By calculating the intensity ratios between the LUMO bands and the two deeper bands （HOMO and HOMO- 1）, we estimate the amount of the charges transferred from Ag（100） to C60 within the range of 1 e to 1.8 e. The results dismay the expectation of surface superconductivity and afford a good reference for further studies of the monolayer C60/Ag（100） system.展开更多
The coordination number of the gadolinium atom and bond distances in the crystal of inonomeric porphyrinate,[Gd(TPP)acac-8H2O 3TCB] (TCB: 1,2,4-trichlorobenzene,acac: anion of acetylacetone),were determined by EXAFS m...The coordination number of the gadolinium atom and bond distances in the crystal of inonomeric porphyrinate,[Gd(TPP)acac-8H2O 3TCB] (TCB: 1,2,4-trichlorobenzene,acac: anion of acetylacetone),were determined by EXAFS method.The Gd atom is eight-coordinated to the four nitrogen atoms of a tetraphenylporphyrin ring,to the two oxygen atoms of one acetylacetonato anion and to two water molecules with Gd-N=0.232 nm,Gd-O=0.243 nm.展开更多
基金Supported by the National Natural Science Foundation of China,No.19234010.
文摘Electron band structure of C_(60) single crystal has been investigated using synchrotron radiation.On the cleaved(111)surface of the C_(60) single crystal the angle-resolved ultraviolet photoelectron spectra were measured at normal emission with varying photon energy from 12.7 to 28.2eV.The valence band dispersions in L-r-L direction were successfully observed.The dispersions are 0.14 and 0.17eV for the highest occupied molecular orbitals(HOMO)and HOMO-1 derived band respectively.
文摘Small Angle X-ray Scattering (SAXS) experiment using Synchrotron Radiation as X-ray source was used to determine the average wall thickness of mesoporous silica prepared by condensation of tetraethylorthosilicate (TEOS) using non-ionic alkylpolyethyleneoxide (AEO(9)) surfactant as templates. The results agreed with that of high-resolution TEM (HRTEM) measurement.
基金Supported by the National Natural Science Foundation of China No.19174003One of authors,Xun Kun,is also indebted to Shandong Province for support through Grant No.90A1111.
文摘For submonolayer amounts of C_(60)condensed on Sn substrate,the peaks derived from top two occupied molecular orbitals were broadened by 0.3eV in comparison with solid C_(60).For coverageθ<1 monolayer,the broadenings are independent of the coverage.It indicates that the delocalizations of electrons in valence bands of C_(60)are weak and the widths do not reflect the true band dispersions.
文摘K3C60 single crystal film was prepared on the cleaved (111) surface of C60 single crystal. Synchrotron radiation angle-resolved photoemission spectra were measured at normal emission with sample temperature at - 150K. Up to four subpeaks of LUMO-derived band were observed. These sub-peaks exhibit distinct energy dispersions which resemble in general the theoretical ones calculated for K3C60 at low temperature with the so-called one-dimensional disordered structure. But there is large deviation of experimental sub-band intervals from the theoretical values. This result is meaningful for the studies of the physical properties of alkali-doped C60 solids, e.g. the mechanism for superconductivity.
基金Supported by National Natural Science Foundation of China (10674115)Beijing Synchrotron Radiation Facility
文摘The synchrotron radiation angle-resolved photoemission data of K3C60 single crystal film are analyzed, aiming at the photoionization cross-sections of the LUMO, HOMO and HOMO-1 bands in low photon energy region （14.5--27.5 eV）. Many fine structures of the HOMO/HOMO-1 intensity ratios are observed, which support the general validity of a quantum chemistry model. However, the experimental data and the theoretical results have some disagreement in the energy positions and magnitudes of the fine structures, and the disagreement is more outstanding than the case of pure C60. So the photoemission data of K3C60 afford valuable experimental reference to further theoretical developments. The LUMO cross-section data, which cannot be discussed with the quantum chemistry description due to strong solid state effects, are also reported for further studies.
基金Supported by National Natural Science Foundation of China (10674115)BSRFRDF of NJUST (AB96331)
文摘We have measured the synchrotron radiation photoelectron spectra of monolayer C60on Ag（100）, By calculating the intensity ratios between the LUMO bands and the two deeper bands （HOMO and HOMO- 1）, we estimate the amount of the charges transferred from Ag（100） to C60 within the range of 1 e to 1.8 e. The results dismay the expectation of surface superconductivity and afford a good reference for further studies of the monolayer C60/Ag（100） system.
基金Project supported by the National Natural Science Foundation of China (No. 29701002)the Sate Educational Committee of ChinaShandong University of China
文摘The coordination number of the gadolinium atom and bond distances in the crystal of inonomeric porphyrinate,[Gd(TPP)acac-8H2O 3TCB] (TCB: 1,2,4-trichlorobenzene,acac: anion of acetylacetone),were determined by EXAFS method.The Gd atom is eight-coordinated to the four nitrogen atoms of a tetraphenylporphyrin ring,to the two oxygen atoms of one acetylacetonato anion and to two water molecules with Gd-N=0.232 nm,Gd-O=0.243 nm.
