Open Access. Powered by Scholars. Published by Universities.®

Physics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 7 of 7

Full-Text Articles in Physics

Optical Properties And Electronic Structure Of Mgausn, S. J. Lee, J. M. Park, T. A. Wiener, L. L. Miller, David W. Lynch Sep 2001

Optical Properties And Electronic Structure Of Mgausn, S. J. Lee, J. M. Park, T. A. Wiener, L. L. Miller, David W. Lynch

Physics and Astronomy Publications

The optical conductivity spectrum of single-crystal MgAuSn was measured by spectroscopic ellipsometry in the energy range 1.5–5.0 eV. The spectrum has a large peak at 2.9 eV and a small shoulder around 4.3 eV. The band structure, density of states, and interband contribution to the optical conductivity were calculated with the tight-binding linear muffin-tin orbital method in the atomic-sphere approximation. The intraband contribution to the optical conductivity was added using the Drude response fitted to the experimental data. The total theoretical spectrum, including the intraband contribution, agrees well with experimental data.


Measurement Of The Midrapidity Transverse Energy Distribution From Root(Nn)-N-S=130 Gev Au+Au Collisions At Rhic, K. Adcox, Sergey Belikov, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Athanasios Petridis, Marzia Rosati, F. K. Wohn, Et Al., Phenix Collaboration Jul 2001

Measurement Of The Midrapidity Transverse Energy Distribution From Root(Nn)-N-S=130 Gev Au+Au Collisions At Rhic, K. Adcox, Sergey Belikov, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Athanasios Petridis, Marzia Rosati, F. K. Wohn, Et Al., Phenix Collaboration

Physics and Astronomy Publications

The first measurement of energy produced transverse to the beam direction at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory is presented. The midrapidity transverse energy density per participating nucleon rises steadily with the number of participants, closely paralleling the rise in charged-particle density, such that ⟨ET⟩/⟨Nch⟩ remains relatively constant as a function of centrality. The energy density calculated via Bjorken’s prescription for the 2% most central Au+Au collisions at √sNN=130GeV is at least εBj=4.6 GeV/fm3, which is a factor of 1.6 larger than found at √sNN=17.2 GeV ( Pb+Pb ...


Optical Properties Of Rni2b2c (R=Y,Tb,Er,Dy), S. J. Lee, B. K. Cho, Paul C. Canfield, David W. Lynch May 2001

Optical Properties Of Rni2b2c (R=Y,Tb,Er,Dy), S. J. Lee, B. K. Cho, Paul C. Canfield, David W. Lynch

Physics and Astronomy Publications

The optical properties of single crystals of RNi2B2C (R=Y,Tb,Er, and Dy) were measured between 1.7 and 5.2 eV at room temperature using a spectroscopic ellipsometer. The spectra for all compounds are similar and the peak positions appear in a similar energy region. The similarity of the spectra of RNi2B2C (R=Tb,Er,Dy) to that of YNi2B2C indicates that the rare-earth 4f states are not actively involved in the optical transitions.


No Well-Defined Remnant Fermi Surface In Sr2cuo2cl2, S. Haffner, D. P. Brammeier, C. G. Olson, L. L. Miller, David W. Lynch Apr 2001

No Well-Defined Remnant Fermi Surface In Sr2cuo2cl2, S. Haffner, D. P. Brammeier, C. G. Olson, L. L. Miller, David W. Lynch

Physics and Astronomy Publications

In angle-resolved photoelectron spectra of the antiferromagnetic insulators Ca2CuO2Cl2 and Sr2CuO2Cl2, a sharp drop of the spectral intensity of the lowest-lying band is observed along a line in k space equivalent to the Fermi surface of the optimally doped high-temperature superconductors. This was interpreted as a signature of the existence of a remnant Fermi surface in the insulating phase of the high-temperature superconductors. In this paper it is shown that the drop of the spectral intensity is not related to the spectral function but is a consequence of the electron-photon matrix element.


Centrality Dependence Of Charged Particle Multiplicity In Au-Au Collisions At Root(S)Nn=130 Gev, K. Adcox, Sergey Belikov, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Athanasios Petridis, Marzia Rosati, F. K. Wohn, Et. Al, Phenix Collaboration Apr 2001

Centrality Dependence Of Charged Particle Multiplicity In Au-Au Collisions At Root(S)Nn=130 Gev, K. Adcox, Sergey Belikov, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, Athanasios Petridis, Marzia Rosati, F. K. Wohn, Et. Al, Phenix Collaboration

Physics and Astronomy Publications

We present results for the charged-particle multiplicity distribution at midrapidity in Au-Au collisions at roots(NN) = 130 GeV measured with the PHENIX detector at RHIC. For the 5% most central collisions we find dN(ch)/d eta (|eta =0) = 622 +/- 1(stat) +/- 41(syst). The results, analyzed as a function of centrality show a steady rise of the particle density per participating nucleon with centrality.


Optical And Magneto-Optical Investigation On Electronic Structure Of Ordered Ferromagnetic Fe3pt, K. J. Kim, S. J. Lee, T. A. Wiener, David W. Lynch Jan 2001

Optical And Magneto-Optical Investigation On Electronic Structure Of Ordered Ferromagnetic Fe3pt, K. J. Kim, S. J. Lee, T. A. Wiener, David W. Lynch

Physics and Astronomy Publications

The optical and magneto-opticalproperties of ordered Fe3Pt have been investigated by spectroscopicellipsometry and magneto-opticalKerrspectroscopy. The diagonal component of the optical conductivity tensor of the compound exhibits a broad absorption peak at about 2 eV, which is shifted by about 0.5 eV to lower energies from the corresponding one in pure bcc Fe. The Kerr angle spectrum of the compound disperses quite similarly in both spectral trend and magnitude to that of pure Fe below 3.5 eV but differently above it. The lower-energy shift of the 2-eV-absorption structure of the compound is interpreted as due to the shift of ...


Fe−3s Core-Level Splitting And Local Magnetism In Fe2val, Ye Feng, M. V. Dobrotvorska, James W. Anderegg, C. G. Olson, David W. Lynch Jan 2001

Fe−3s Core-Level Splitting And Local Magnetism In Fe2val, Ye Feng, M. V. Dobrotvorska, James W. Anderegg, C. G. Olson, David W. Lynch

Physics and Astronomy Publications

X-ray and soft x-ray photoelectron spectra were taken on Fe2VAl samples. The Fe−3s spectra show a shoulder on the higher binding energy side of the main peak, split by ≈4.7 eV. Based on current understanding of core-level multiplet splitting in transition-metal compounds, we believe this is direct evidence of a local moment in Fe2VAl.