Browsing by Author "Geldart, D. J. W."
Now showing items 1-20 of 46
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Adsorbate densities and surface potentials of physisorbed systems: A density-functional approach
Payne, S. H.; Kreuzer, H. J.; Geldart, D. J. W. (1987-06/15)A density-functional approach for the calculation of the density of particles adsorbed on the surface of a solid is explored including the adparticle two-body interaction. The coverages and effective surface potentials so ... -
Analytical structure of the wave-number-dependent susceptibility of many-fermion systems at low temperature and long wavelength. II
Geldart, D. J. W.; Rasolt, M. (1980-10/15)For pt.I see ibid., vol.15, p.1523 (1977). It is shown that the nonanalytic structure of the wave-number-dependent susceptibility noted by Geldart and Rasolt is not removed by including repeated particle-particle scattering -
Anharmonicity and cross section for absorption of radiation by water dimer
Tso, H. C. W.; Geldart, D. J. W.; Chylek, P. (AIP, 1998-04/01)We calculate the absorption cross section of water dimer molecules in thermal equilibrium at temperatures typical of the lower atmosphere using quantum mechanical coupled nonlinear equations of motion. Empirical Morse-oscillator ... -
Anisotropy of the critical magnetic susceptibility of gadolinium
Geldart, D. J. W.; Hargraves, P.; Fujiki, N. M.; Dunlap, R. A. (1989-06/05)The magnetic susceptibility along the c axis (xc) and in the basal plane (xb) has been measured on a single crystal of Gd in the reduced temperature range 410-4t1.310-2. Uniaxial anisotropy is observed. Magnetic dipole-dipole ... -
Coefficients to O(3) for the mixed fixed point of the nm-component field model
De'Bell, K.; Geldart, D. J. W. (1985-10/01)The nm-component field model has a number of application in the description of critical phenomena. The coefficients in the expansion for the stability matrix eigenvalues and correlation function exponent n for the mixed ... -
Comment on `Anisotropic superconductors with repulsive average interaction'
Leavens, C. R.; MacDonald, A. H.; Geldart, D. J. W. (1982-10/01)For original paper see M.D. Whitmore and J.P. Carbotte, ibid., vol.23, p.5782 (1981). In a recent paper Whitmore and Carbotte concluded that a sufficient condition for the superconducting state to be stable relative to the ... -
Comment on `Exact electron-gas response functions at high density'
Rasolt, M.; Geldart, D. J. W.; Langreth, D. C.; Vosko, S. H. (1988-05/09)For original paper see D.C. Langreth and S.H. Vosko, ibid., vol.59, p.497 (1987). Langreth and Vosko calculated correlation contributions to the Hohenberg-Kohn energy response function Kxc(q,k). They claimed that the results ... -
Comment on `Quantum-mechanical interpretation of the exchange-correlation potential of Kohn-Sham density-functional theory'
Rasolt, M.; Geldart, D. J. W.; Harbola, M. K.; Sahni, V. (1990-07/09)For original paper see M.K. Harbola and V. Sahni, ibid., vol.62, p.489 (1989). Harbola and Sahni suggested a procedure for constructing the exchange-correlation potential that enters the Kohn-Sham single-particle equations. ... -
Contribution of water vapor dimers to clear sky absorption of solar radiation
Chylek, P.; Fu, Q.; Tso, H. C. W.; Geldart, D. J. W. (Swedish Geophys. Soc, 1999-03)Using previously derived-values of the water vapor dimer spectral absorption cross section we calculate the water vapor dimer contribution to the clear sky absorption of solar radiation. We consider the water dimer ... -
Convergence properties as a function of spatial dimensionality of gradient expansions for the ground-state energy of an inhomogeneous electron gas
Geldart, D. J. W.; Gumbs, G. (1986-02/15)The extended Thomas-Fermi approximation for the ground-state energy of a many-fermion system is generalized to arbitrary spatial dimension. The authors' objective is a better understanding of convergence properties of such ... -
Critical behavior of two-dimensional magnetic systems with dipole-dipole interactions
De'Bell, K.; Geldart, D. J. W. (1989-01/01)The critical exponents of two-dimensional dipolar magnetic systems with isotropic in-plane ordering may be obtained from the expansion which determines the exponents of isotropic three-dimensional dipolar systems. However, ... -
Critical exponents and amplitude ratios from electrical resistivity measurements of dysprosium
Malmstrom, G.; Geldart, D. J. W. (1980-02/01)Resistive anomalies in helical antiferromagnets are shown to reflect the temperature dependence of the specific heat sufficiently close to the Neel temperature. The temperature dependence of superzone energy gaps does not ... -
Critical magnetic susceptibility of gadolinium
Dunlap, R. A.; Fujiki, N. M.; Hargraves, P.; Geldart, D. J. W. (1994-11/15)No abstract available. -
Critical magnetic susceptibility of gadolinium
Hargraves, P.; Dunlap, R. A.; Geldart, D. J. W.; Ritcey, S. P. (1988-08/01)The magnetic suspectibility of a single crystal of high-purity gadolinium has been measured in the critical region with use of AC susceptibility methods. For reduced temperatures t10-3, the data are described by a simple ... -
Density dependence of critical magnetic fields at the metal-insulator bifurcation in two dimensions
Geldart, D. J. W.; Neilson, D. (APS through AIP, 2003-01/15)The density dependence of the critical in-plane magnetic field Bc at the bifurcation of the resistivity of two-dimensional electron systems with low levels of disorder is determined using the spin-polarization dependence ... -
Depth-dependent static shielding of an impurity by a quantum plasma in a magnetic field
Gumbs, G.; Geldart, D. J. W. (1984-05/15)The static shielding of a charged impurity embedded in a quantum plasma is studied with the use of linear-response theory. The required response function is calculated in the random-phase approximation with a uniform ... -
Diamagnetic susceptibility of a dense electron gas
Vignale, G.; Rosolt, M.; Geldart, D. J. W. (1988-02/15)The authors calculate the diamagnetic susceptibility of a uniform interacting electron gas in the random-phase approximation. From this the exact high-density expansion of the diamagnetic susceptibility is obtained -
Dipole-dipole interactions and the critical resistivity of gadolinium
Geldart, D. J. W.; De'Bell, K.; Cook, J.; Laubitz, M. J. (1987-06/01)Results are presented for the electrical resistivity of a c-axis single crystal of high-purity gadolinium metal in the immediate vicinity of the Curie temperature. Numerical analysis reveals that the data are not well ... -
Effect of finite mean free path on spin-flip scattering rates near the critical point of magnetically ordered systems
Geldart, D. J. W.; De'Bell, K. (1985)The finite electron mean free path of conduction electrons is found to play an important role in determining spin-flip scattering rates, 1/sf, near a magnetic critical point. Small-momentum-transfer processes are suppressed ... -
Exchange and correlation energy in a nonuniform fermion fluid
Rasolt, M.; Geldart, D. J. W. (1986-07/15)Recent results for the surface energy of jelliumlike surfaces are investigated within the functional-density formalism. These results along with first-principles considerations support the contention that the first gradient ...