Real-time radiology in the microscale (2006)
Hwu, Y., Je, J. H., Margaritondo, G.
We present several examples of the applications of a novel microradiology approach based on phase contrast enhancement using unmonochromatized synchrotron X-rays. The approach-mostly implemented and...
Synchrotron refractive-index microradiography of human liver cancer tissue (2006)
Tong, Y. P., Zhang, G. L., Li, Y., Hwu, Y., Tsai, W., Ho, J. E. J., ...
Three human liver tissue samples (similar to 5 mm x 40 mm x 20 mm) were excised from a cancer patient's liver during surgery. The microradiology analysis was performed with a non-standard approach on...
Synchrotron microradiography study on acute lung injury of mouse caused by PM2.5 aerosols (2006)
Tong, Y. P., Zhang, G. L., Li, Y., Tan, M. G., Wang, W., Chen, J. M., ...
In order to investigate FeSO4, ZnSO4 (the two of main metal compositions of Shanghai PM2.5 (particle matter with those aerodynamical diameter
Imaging cells and tissues with refractive index radiology (2006)
Hwu, Y., Tsai, W. L., Chang, H. M., Yeh, H. I., Hsu, P. C., Yang, Y. C., ...
Can individual cells, including live cells, be imaged using hard x rays? Common wisdom until now required sophisticated staining techniques for this task. We show instead that individual cells and...
Synchrotron light in medical and materials science radiology (2006)
Margaritondo, G., Hwu, Y., Je, J. H.
Radiology is the oldest and by far the largest field of application of X-rays. In recent years, this domain has been literally revolutionized by the exploitation of the unique characteristics of...
Real-time radiology in the microscale (2006)
Hwu, Y., Je, J. H., Margaritondo, G.
We present several examples of the applications of a novel microradiology approach based on unmonochromatized synchrotron x-rays. The approach - mostly implemented on the ICPCIR (International...
Baik, S., Kim, H. S., Jeong, M. H., Lee, C. S., Je, J. H., Hwu, Y., ...
We describe the general characteristics and the first result of a new synchrotron beamline at the Pohang Light Source in Korea. The beamline, operated by a Korean-Taiwanese-Swiss consortium, is...
Synchrotron radiation in radiology: radiology techniques based on synchrotron sources (2006)
Meuli, R., Hwu, Y., Je, J. H., Margaritondo, G.
The characteristics of synchrotron X-ray sources-quite different from those of conventional sources-are exploited by several new imaging techniques. These techniques expand the capabilities of...
Seol, S. K., Yi, J. M., Jin, X., Kim, C. C., Je, J. H., Tsai, W. L., ...
Localized electrochemical deposition (LECD) is an emerging technology for inexpensive and effective fabrication of high-aspect-ratio microstructure of diverse materials. Microradiology with coherent...
Synchrotron microangiography with no contrast agent (2006)
Hwu, Y., Tsai, W. L., Je, J. H., Seol, S. K., Kim, B., Groso, A., ...
Coherent x-rays from synchrotron sources are increasingly used in non-conventional radiological techniques ('phase-contrast' radiology). Our experiments demonstrate that by using white...
Gutkin, M. Y., Sheinerman, A. G., Argunova, T. S., Mokhov, E. N., Je, J. H., Hwu, Y., ...
By using synchrotron radiation phase sensitive radiography we have examined the reactions of screw superdislocations or micropipes in silicon carbide single crystals: bundling, twisting, and...
Electron-Energy-Loss Spectroscopy of Cleaved Single-Crystal Yba2cu3o7-X (2006)
Chang, Y., Hwu, Y., Onellion, M., Margaritondo, G., Morris, P. A., Bonner, W. A.
Soft-X-Ray Photoemission-Study of the Electronic-Structure of Bi4ca3sr3cu4o16+X (2006)
Zanoni, R., Chang, Y., Tang, M., Hwu, Y., Onellion, M., Margaritondo, G., ...
New Electronic-Properties of Metal/Iii-V Compound Semiconductor Interfaces (2006)
Brillson, L. J., Viturro, R. E., Chang, S., Shaw, J. L., Mailhiot, C., Zanoni, R., ...
Photoemission-Studies of Silicon Chemisorption on Al(110) (2006)
Chang, Y., Hansen, J. C., Zanini, F., Hwu, Y., Margaritondo, G.
Schottky-Barrier Formation by Silicon Deposition on Unreactive and Reactive Metal Substrates (2006)
Chang, Y., Hanson, J., Hwu, Y., Zanini, F., Margaritondo, G.
Nature of the Schottky Term in the Schottky-Barrier (2006)
Chang, Y., Hwu, Y., Hansen, J., Zanini, F., Margaritondo, G.
Low-Energy Excitations in Cu-O-Based Superconductors with Electron-Energy-Loss Spectroscopy (2006)
Kelly, M. K., Meng, Y., Hwu, Y., Chang, Y., Chen, Y., Lapeyre, G. J., ...
Polycrystalline and Highly Oriented Graphite - Differences in the Photoemission Spectra (2006)
Costanzo, E., Faraci, G., Pennisi, A. R., Terrasi, A., Hwu, Y., Margaritondo, G.
Silver-Bisrcacuo Chemical-Reactions (2006)
Hwu, Y., Marsi, M., Hwang, C., Seutjens, J., Larbalestier, D. C., Onellion, M., ...
Valence Electronic-Structure of Thallium-Compound High-Temperature Superconductors (2006)
Hwu, Y., Marsi, M., Terrasi, A., Onellion, M., Huber, D. L., Margaritondo, G., ...
We used photoemission spectroscopy with synchrotron radiation to investigate the electronic structure of eight different thallium cuprates: pure Tl2.2Ba2CuO(y), Ce-doped Tl2.2Ba(2-x)Ce(x)CuO(y) (x =...
Controlled Modification of Heterojunction Band Lineups by Diffusive Intralayers (2006)
McKinley, J. T., Hwu, Y., Rioux, D., Terrasi, A., Zanini, F., Margaritondo, G., ...
Search for the 1+ State of Copper in the Electron Superconductor Nd2-Xcexcuo4 (2006)
Terrasi, A., Hwu, Y., Rioux, D., Marsi, M., Chang, Y., McKinley, J. T., ...
Substitutional Reactions in the Surface-Chemistry of Bicasrcuo (2006)
Hwu, Y., Lozzi, L., Larosa, S., Marsi, M., Onellion, M., Berger, H., ...
We identified the nature of the chemical reaction between silver and the cleaved surface of BiCaSrCuO at room temperature as a Bi-Ag reaction with Bi segregation, accompanied by interaction with the...
Bicasrcuo-Semiconductor Interface Formation Processes (2006)
Hwu, Y., Lozzi, L., Larosa, S., Marsi, M., Onellion, M., Berger, H., ...
The deposition of Si and Ge on single-crystal 2212 BiCaSrCuO was studied with synchrotron-radiation photoemission. Contrary to previous results on polycrystalline substrates, clear evidence was found...
Evidence for Surface Chemical-Reactions between Gold and Bicasrcuo (2006)
Hwu, Y., Lozzi, L., Larosa, S., Onellion, M., Berger, H., Gozzo, F., ...
We explored the reactivity of gold on cleaved 2212 BiCaSrCuO by synchrotron-radiation photoemission spectroscopy. We found no evidence for reactivity when the substrate was at room temperature,...
Electronic-Spectrum of the High-Temperature Superconducting State (2006)
Hwu, Y., Lozzi, L., Marsi, M., Larosa, S., Winokur, M., Davis, P., ...
Improved experimental conditions enabled us to increase the signal-to-noise ratio of the photoemission spectra for the superconducting state of Bi2Ca2SrCu2O8, taken with high angular and energy...
Valence State of Copper in Nd2-Xcexcuo4 (2006)
Hwu, Y., Marsi, M., Terrasi, A., Rioux, D., Chang, Y., McKinley, J. T., ...
New photoemission data are presented for a series of Ce-doped or undoped, reduced or nonreduced, Nd cuprates. The data, taken with high signal-to-noise level in the constant-initial-state mode,...
High-Resolution Synchrotron-Radiation Core-Level Spectroscopy of Decapped Gaas(100) Surfaces (2006)
Lelay, G., Mao, D., Kahn, A., Hwu, Y., Margaritondo, G.
We report a high-resolution core-level spectroscopy study of the (4 x 2)-c(8 x 2) GaAs(100) surface prepared by thermal decapping of surfaces grown by molecular-beam epitaxy. Ga and As 3d core levels...
Mao, D., Kahn, A., Lelay, G., Marsi, M., Hwu, Y., Margaritondo, G., ...
Contact potential difference (CPD) measurements using a Kelvin probe coupled with synchrotron radiation are used to investigate various aspects of the problem of surface photovoltage (SPV) induced by...
Control of Ge Homojunction Band Offsets Via Ultrathin Ga-as Dipole Layers (2006)
McKinley, J. T., Hwu, Y., Koltenbah, B. E. C., Margaritondo, G., Baroni, S., Resta, R.
We have created 0.35-0.45 eV band offsets at Ge homojunctions using Ga-As dipole intralayers, with the Ge valence band edge on the As side of the junction at lower energy. This is, to our knowledge,...
Valence-Band States of Ion-Bombarded Polystyrene (2006)
Terrasi, A., Foti, G., Hwu, Y., Margaritondo, G.
Ion-bombarded polystyrene with a 0.5-keV Ar+ beam has been investigated by means of photoelectron spectroscopy performed with synchrotron radiation. After a dose of 10(15) ions/cm2 the evolution of...
Photoelectron-Spectroscopy of Silver Clusters (2006)
Faraci, G., Costanzo, E., Pennisi, A. R., Hwu, Y., Margaritondo, G.
A comparison of x-ray photoemission from Ag clusters deposited on polygraphite and highly oriented pyrolitic graphite shows the influence of the support both on the valence band and on the core 3 d...
Photoemission near the Fermi Energy in One Dimension (2006)
Hwu, Y., Almeras, P., Marsi, M., Berger, H., Levy, F., Grioni, M., ...
Angle-resolved photoemission spectra taken with high energy resolution on the one-dimensional compound (TaSe4)2I confirm the suppression of the spectral intensity at the Fermi edge for...
Hwu, Y., Lozzi, L., Larosa, S., Onellion, M., Almeras, P., Gozzo, F., ...
We measured at high energy and angular resolution the spectral width of photoemission features near the Fermi energy for Ag(100) and for the nearly-two-dimensional metal 2H-NbSe2. The results do not...
Microscopic Schottky-Barrier Control - Semiconductor-on-Metal Case (2006)
Hwu, Y., Marsi, M., Almeras, P., Margaritondo, G.
We have modified the Schottky-barrer height of Si overlayers on Ag(111) substrates by means of Cs intralayers of different thicknesses. We also found a correlation between these changes and those of...
Mao, D., Kahn, A., Lelay, G., Marsi, M., Hwu, Y., Margaritondo, G.
Contact potential difference (CPD) measurements using a Kelvin probe coupled with synchrotron radiation are used to investigate the surface photovoltage (SPV) induced by synchrotron radiation at GaAs...
Mao, D., Santos, M., Shayegan, M., Kahn, A., Lelay, G., Hwu, Y., ...
A study of the formation of In- and Au-GaAs(100) interfaces is reported. The metal overlayers are deposited in ultrahigh vacuum on room-temperature (RT) and low-temperature (LT) (100)GaAs grown by...
Microscopic Manipulation of Homojunction Band Lineups (2006)
Marsi, M., Larosa, S., Hwu, Y., Gozzo, F., Coluzza, C., Baldereschi, A., ...
We tested the theoretical prediction that the band structures on the opposite sides of a homojunction can be artificially displaced in energy with respect to each other by means of double intralayers...
Homojunction Band Discontinuities Induced by Dipolar Intralayers - Al-as in Ge (2006)
Marsi, M., Larosa, S., Hwu, Y., Margaritondo, G.
The possibility of inducing a band offset in the electronic structure of Ge homojunctions has been recently demonstrated using Ga-As double layers. A photoemission study is presented in which it is...
Control of Ge-Homojunction Band Offsets Via Ultrathin Ga-as Dipole Layers (2006)
McKinley, J. T., Hwu, Y., Koltenbah, B. E. C., Margaritondo, G., Baroni, S., Resta, R.
Band offsets of 0.35-0.45 eV are produced at Ge homojunctions by placing a monolayer of As and an adjacent monolayer of Ga between the two Ge bulks. The "Ga-first" and "As-first" growth sequences...
Early Stages of Schottky-Barrier Formation for Al Deposited on Gaas(110) (2006)
Ortega, J., Garciavidal, F. J., Perez, R., Rincon, R., Flores, F., Coluzza, C., ...
Schottky-barrier formation for Al on GaAs(110) was analyzed theoretically and with the aid of synchrotron-radiation photoemission experiments as a function of the metal coverage. For various...
Binding-Energies and Cluster Formation at Low Metal-Deposition - Ag on Si and Sio2 (2006)
Pennisi, A. R., Costanzo, E., Faraci, G., Hwu, Y., Margaritondo, G.
A comparison of photoemission spectra from Ag clusters deposited on silicon oxide and on cleaved silicon substrate has allowed us to discriminate initial and final state effects in the binding...
Photoemission by Synchrotron Radiation from Fe/Si, Co/Si and (Fe-Co)/Si Interfaces (2006)
Terrasi, A., Campisano, S. U., Rimini, E., Hwu, Y., Margaritondo, G.
In this work the interface between transition metals (Fe, Co) and Si has been investigated by soft X-ray photoemission spectroscopy. Synchrotron radiation has been used as photon source, measuring...
High-Resolution Tests of Low-Dimensionality Effects in Photoemission (2006)
Coluzza, C., Berger, H., Almeras, P., Gozzo, F., Margaritondo, G., Indlekofer, G., ...
High-energy-resolution photoemission spectra, taken on three quasi-one-dimensional crystals, TaTe4, NbTe4, and (NbSe4)3I confirm the general phenomenon of the suppression of the photoemission...
Temperature-Dependence of the Heterojunction Band-Offset - Si on Inp(110) (2006)
Dellorto, T., Destasio, G., Capozi, M., Ottaviani, C., Quaresima, C., Perfetti, P., ...
We present a photoemission study of the initial growth stages of amorphous Si on the InP(110) cleaved surface, performed at 120 K and compared with the room-temperature (RT) results. Deposition at...
Search for Photoinduced Dipoles at Heterojunction Interfaces (2006)
Dellorto, T., Destasio, G., Capozi, M., Ottaviani, C., Quaresima, C., Perfetti, P., ...
We tried to apply the mechanism of surface photovoltage (SPV) to a particular class of semiconductor heterojunctions, those having staggered gaps, with the aim of photoinducing charges of opposite...
Evidence for Pd Bonding with Si Intermediate Oxidation-States (2006)
Faraci, G., Larosa, S., Pennisi, A. R., Hwu, Y., Lozzi, L., Margaritondo, G.
The bonding of Pd atoms evaporated on a thin layer of silicon intermediate oxidation states has been studied by core level and valence band photoemission spectroscopy. The particular substrate was...
Evidence for a New Aluminum Oxidation-State (2006)
Faraci, G., Larosa, S., Pennisi, A. R., Hwu, Y., Margaritondo, G.
We present experimental evidence of a previously unknown aluminum oxidation state due to chemisorbed atomic oxygen. This new oxidation state has been detected at room temperature on the chemically...
Lifetime Broadening in Bulk Photoemission Spectroscopy - Reply (2006)
Hwu, Y., Lozzi, L., Larosa, S., Onellion, M., Almeras, P., Gozzo, F., ...
The comment by Starnberg, Brauer, and Nilsson qualitatively identifies the final-state lifetime as the cause of the ''anomalous'' photoemission broadening, but it neglects the linear energy...
Al Intermediate Oxidation-States Observed by Core-Level Photoemission Spectroscopy (2006)
Faraci, G., Larosa, S., Pennisi, A. R., Hwu, Y., Margaritondo, G.
Aluminum oxidation states in stoichiometric or substoichiometric configuration are studied by core level photoemission spectroscopy on different substrates (SiO2, graphite). They are compared with...
Hwu, Y., Tung, C. Y., Pieh, J. Y., Lee, S. D., Almeras, P., Gozzo, F., ...
The first photoelectron spectromicroscopy experiments at the new 1.3 GeV ultrabright X-ray source of SRRC have produced interesting results concerning chemical and topographic features in three types...
Schottky barrier at the Au/Gap(110) interface (2006)
Fanfoni, M., Goletti, C., Chiaradia, P., Ng, W., Cerrina, F., Hwu, Y., ...
The Schottky-barrier formation of the Au/GaP (110) interface has been investigated by photoemission, in the presence of large surface photovoltage effects induced by the intense photon beam of a...
In 1993/94, ultrabright synchrotron sources of soft X-rays have been commissioned in Taiwan, in Italy and in the USA - and another one is forthcoming in South Korea, The novel field of photoelectron...
Coherent x-rays in the world of nanoscience (2006)
Margaritondo, G., Tromba, G., Hwu, Y., Grioni, M.
Coherent x-rays are here! This exciting news is a byproduct of the effort to increase the brightness of synchrotron light sources. We discuss the basic issues concerning x-ray coherence, and some of...
Coherence-enhanced synchrotron radiology: Refraction versus diffraction mechanisms (2006)
Hwu, Y., Hsieh, H. H., Lu, M. J., Tsai, W. L., Lin, H. M., Goh, W. C., ...
Tests performed in different regimes reveal the interplay of two edge-enhancement mechanisms in radiological images taken with coherent synchrotron light. The relative weight of the two mechanisms,...
Coherence based contrast enhancement in x-ray radiography with a photoelectron microscope (2006)
Hwu, Y., Lai, B., Mancini, D. C., Je, J. H., Noh, D. Y., Bertolo, M., ...
We show that a photoelectron spectromicroscope of the photoelectron emission microscope type can be used as an x-ray imaging detector for radiology. Using high penetration hard-x-ray photons...