Select Subject

All (8831)

Agronomy (158)

Animal Husbandry,... (64)

Aquatic Science (16)

Astronomy (36)

Aviation (22)

Basic Medicine (184)

Biology (504)

Chemical Engineering (103)

Chemistry (635)

Civil and Archite... (105)

Clinical Medicine (236)

Computer Science ... (924)

Dynamic and Elect... (121)

Earth Science (119)

Economics (67)

Education (31)

Electrics, Commun... (927)

Energy Science an... (67)

Engineering and T... (15)

Environmental Sci... (140)

Food Science and ... (63)

Forestry (36)

Hydraulic Enginee... (40)

Mechanics (240)

Metallurgical Eng... (32)

Mine Engineering ... (38)

Nuclear Science a... (21)

Pharmacy (98)

Physics (920)

Preventive Medici... (37)

Psychology (20)

Security Science ... (17)

Sports Science (6)

Surveying and Map... (15)

Textile Science a... (16)

Traditional Chine... (56)

Transportation En... (57)

Select/Unselect all

For Selected Papers

Saved Papers

Please enter a name for this paper to be shown in your personalized Saved Papers list


	1. Localized charge polarization by less-coordination: Rh adatoms, step edges, and added rows
	Sun Changqing
	Physics 02 November 2009
	Show/Hide Abstract \| Cite this paper︱Full-text: PDF (0 B)

	Abstract:The revolutionary impact of atomic under-coordination is indeed fascinating, which discriminates the processes of catalytic reaction and growth nucleation at defect sites from those at a flat surface, with mechanism that needs urgently to be known. A difference between the XPS Rh 3d5/2 spectra with and without artificial undercoordination reveals herewith excitingly that adatoms, step edge atoms, and atoms near the missing-row vacancies do induce localized polarization of the otherwise conductive s-electrons by the densely and tightly trapped core electrons; the extent of polarization is more significant for Rh atoms with even lower coordination numbers. The core electrons trapping happens because of the shorter and stronger local bonds and the associated quantum well depression.
	TO cite this article:Sun Changqing. Localized charge polarization by less-coordination: Rh adatoms, step edges, and added rows[OL].[ 2 November 2009] http://en.paper.edu.cn/en_releasepaper/content/36318


	2. What can we exactly learn from the XPS measurement of the orientation-resolved surface core level shift?
	Sun Changqing
	Physics 23 September 2009
	Show/Hide Abstract \| Cite this paper︱Full-text: PDF (0 B)

	Abstract:We demonstrated that theoretical reproduction of the Ru(0001) and Ru(10 0) surface X-ray photoelectron emission, for example, can elucidate the following information: (i) the 3d5/2 energy level of an isolated Ru atom = 275.883刡0.002 eV; (ii) the positive shift of = 3.661 eV from upon bulk formation; (iii) the functional expression for the coordination z resolved energy shift: with being the z-dependant bond contraction coefficient of different layers and orientations; (iv) the effective atomic coordination numbers of the surface layers; (v) the z-dependence of the lattice strain, binding energy density gain, and atomic cohesive energy remnant in the surfaces up to skin depth; and importantly, (vi) the physical origin for the positive core level shift as arise from the perturbation of the Hamiltonian by the shorter and stronger bonds between under-coordinated atoms.
	TO cite this article:Sun Changqing. What can we exactly learn from the XPS measurement of the orientation-resolved surface core level shift? [OL].[23 September 2009] http://en.paper.edu.cn/en_releasepaper/content/35412


	3. Atomic-Layer and Crystal-Orientation Resolved Local Strain, Binding Energy, and Potential Trap Depth of the Be(0001), (10 0), and (11 0) Surfaces Elucidated from X-ray Photoelectron Emission Analysis
	Sun Changqing
	Physics 11 September 2009
	Show/Hide Abstract \| Cite this paper︱Full-text: PDF (0 B)

	Abstract:Development of an approach extracting quantitative information regarding the atomic-layer and crystal-orientation resolved local structural relaxation, binding energy and the energetic behavior of electrons in a surface of skin depth from photoelectron emission has long been a great challenge though the surface-induced core level shifts of materials have been intensively investigated. Here we show that a combination of the bond order-length-strength (BOLS) correlation theory and the X-ray photoelectron spectroscope (XPS) has enabled us to derive information, from analyzing the 1s energy shift of Be(0001), (10 0), and (11 0) surfaces, for instance, regarding: (i) the energy levels of an isolated Be (1s: 106.40 eV) atom and its bulk shift (4.72 eV); (ii) the layer- and orientation-resolved effective atomic coordination, local strain, quantum trap depth, binding energy density and atomic cohesive energy of Be surface skins of four atomic layers in depth. It is affirmed that the broken-bond-induced local strain and quantum trapping perturb the Hamiltonian and hence the fascinating behavior of surface electrons. Developed approach can be applied to other systems containing high fraction of under-coordinated atoms such as adatoms, atomic defects and nanostructures to gain quantitative information and deeper understanding of the properties and processes due to coordination imperfection effect.
	TO cite this article:Sun Changqing. Atomic-Layer and Crystal-Orientation Resolved Local Strain, Binding Energy, and Potential Trap Depth of the Be(0001), (10 0), and (11 0) Surfaces Elucidated from X-ray Photoelectron Emission Analysis[OL].[11 September 2009] http://en.paper.edu.cn/en_releasepaper/content/35143


	4. Orientation-resolved 3d5/2 energy shift of Rh and Pd surfaces: Anisotropy of the skin-depth lattice strain and quantum trapping
	Sun Changqing
	Physics 02 September 2009
	Show/Hide Abstract \| Cite this paper︱Full-text: PDF (0 B)

	Abstract:Incorporating the BOLS correlation algorithm [C. Q. Sun, Phys Rev B 69, 045105 (2004); Y. Sun, J Phys Chem C 113, 14696 (2009)] into the high-resolution XPS measurements [J. N. Andersen, et al, Phys Rev B 50, 17525 (1994); A. Baraldi, et al, N J Phys 9, 143 (2007)] has turned out an effective way of determining the 3d5/2 energy levels of the isolated Rh(302.50 eV) and Pd(330.63 eV) atoms and their respective bulk shifts (3.95 and 3.99 eV) with a refinement of the effective atomic coordination numbers of the top (100), (110), and (111) atomic layers (4.00, 3.66, and 4.04). It is further confirmed that bonds between under-coordinated atoms become shorter and stronger, which induces local strain and the skin-depth charge and energy quantum trapping and hence derives the global positive energy shifts.
	TO cite this article:Sun Changqing. Orientation-resolved 3d5/2 energy shift of Rh and Pd surfaces: Anisotropy of the skin-depth lattice strain and quantum trapping[OL].[ 2 September 2009] http://en.paper.edu.cn/en_releasepaper/content/34828


	5. Charge polarization and quantum trapping in AgPd and CuPd bimetallic alloy catalysts
	Sun Changqing
	Physics 26 August 2009
	Show/Hide Abstract \| Cite this paper︱Full-text: PDF (0 B)

	Abstract:AgPd and CuPd alloys are important catalysts that perform very differently with physical origins being still undetermined. Using X-ray photoelectron spectroscopy we examined the density-of-states evolution of the valence and the Cu 2p, Ag 3d, and Pd 3d core bands during the alloying process of ultrathin Cu and Ag films deposited separately on Pd substrates. We found that the valence and the core electrons of the CuPd alloy shift positively, opposite to the occurrences in the AgPd alloy catalyst. This finding may distinguish the CuPd from the AgPd in the catalytic reactions, indicating that CuPd serves as an acceptor due to quantum trapping and the AgPd as a donor because of charge polarization.
	TO cite this article:Sun Changqing. Charge polarization and quantum trapping in AgPd and CuPd bimetallic alloy catalysts[OL].[26 August 2009] http://en.paper.edu.cn/en_releasepaper/content/34655

Select/Unselect all

For Selected Papers

Saved Papers

Please enter a name for this paper to be shown in your personalized Saved Papers list

Rank

Alert Name:
Alerting to:
Authentication email will be sent to your email address in 24 hours
Frequency:
Email Message Format:	Plain text Graphical(HTML)

Complete the form below and we will recommend the selected titles to your friends on your behalf. * Indicates a required field.
Your name*:
Your email address*:
Recipient's name*:
Recipient's email address*:
(multiple recipient's names and email addresses should be separated with semicolons)
Your comments:	I thought you would find the page(s) useful.

Your name:
Your email address:
Recipient's name:
Recipient's email address:
(multiple recipient's names and email addresses should be separated with semicolons)
Your comments:	I thought you would find this page useful.

Disclaimer: This message was sent to your friend using the "Send it to a friend" facility on the Sciencepaper Online’ WWW site, http://www.paper.edu.cn/en. The Sciencepaper Online is not responsible for the content of this email, and anything said in this email does not necessarily reflect the Sciencepaper Online's views.

	Check out RSS, or use RSS reader to subscribe this item