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Articles 1 - 17 of 17
Full-Text Articles in Physical Sciences and Mathematics
Light Scattering Studies Of Orientational Fluctuations Of Cs2, Scott Whittenburg
Light Scattering Studies Of Orientational Fluctuations Of Cs2, Scott Whittenburg
Scott L Whittenburg
We have measured the depolarized Rayleigh relaxation time of CS2 as a function of temperature and concentration in an optically isotropic solvent CCl4. The concentration dependence of the relaxation times indicates the importance of orientational pair correlation in CS2. The orientational pair correlation factor is found to depend on concentration at high CS2 concentration, as well as viscosity and temperature, in contrast to what is observed in other small molecules. The single particle reorientation times were obtained by extrapolating from the depolarized Rayleigh relaxation times to infinite dilution. These were compared with the predictions of the hydrodynamic slip and stick …
A Comparison Of The Rough Sphere Rotational Diffusion Model With Experimental Results For Liquid Methyl Iodide, Scott Whittenburg
A Comparison Of The Rough Sphere Rotational Diffusion Model With Experimental Results For Liquid Methyl Iodide, Scott Whittenburg
Scott L Whittenburg
No abstract provided.
Raman Scattering Study Of Cs2 In Cci4, Scott Whittenburg
Raman Scattering Study Of Cs2 In Cci4, Scott Whittenburg
Scott L Whittenburg
No abstract provided.
Comment On "Depolarized Rayleigh Spectroscopy From Benzonitrile", Scott Whittenburg
Comment On "Depolarized Rayleigh Spectroscopy From Benzonitrile", Scott Whittenburg
Scott L Whittenburg
No abstract provided.
Depolarized Rayleigh Scattering Study Of Pyridine In Cyclohexane, Scott Whittenburg
Depolarized Rayleigh Scattering Study Of Pyridine In Cyclohexane, Scott Whittenburg
Scott L Whittenburg
No abstract provided.
Light Scattering Studies Of Rotational And Vibrational Relaxations Of Acetonitrile In Carbon Tetrachloride, Scott Whittenburg
Light Scattering Studies Of Rotational And Vibrational Relaxations Of Acetonitrile In Carbon Tetrachloride, Scott Whittenburg
Scott L Whittenburg
The rotational and vibrational relaxation times of acetonitrile-carbon tetrachloride solutions were investigated as a function of concentration. viscosity, and temperature using depolarized Rayleigh and Raman scattering. Using a Fabry-Perot interferometer and single frequency laser source, we have shown that reliable results for the single particle orientational correlation times (T,) for -CH3CN can be obtained by carrying out a concentration dependent depolarized Rayleigh scattering study. Raman scattering was shown to yield inconsistent results for T. in CH3CN. At constant viscosity, it was found that the Rayleigh scattering relaxation time (TRay) of CH3CN in CCI. does not change with CH3CN concentration, indicating …
Magnetization Reversal Of Elliptical Co/Cu/Co Pseudo-Spin Valve Dots, Scott Whittenburg
Magnetization Reversal Of Elliptical Co/Cu/Co Pseudo-Spin Valve Dots, Scott Whittenburg
Scott L Whittenburg
We present our recent simulated results on Cr (5 nm)/ Cu (5 nm)/ Co (5 nm)/ Cu (3 nm)/ Co (2 nm) pseudo-spin valve dots. The simulated results agree qualitatively with the experimental results. Three different sizes of elliptical dots, 150 nm3105 nm, 175 nm370 nm, and 200 nm360 nm, were simulated. Our simulations show that in these types of dots magnetization reversal occurs by the formation of domain walls: 90° for 175 nm370 nm and 360° for 200 nm360 nm. No domain wall was observed in the reversal of the 150 nm3105 nm dots. For such dots, the simulated …
Preparation, Structural Characterization, And Dynamic Properties Investigation Of Permalloy Antidot Arrays, Scott Whittenburg, Charles J. O'Connor
Preparation, Structural Characterization, And Dynamic Properties Investigation Of Permalloy Antidot Arrays, Scott Whittenburg, Charles J. O'Connor
Scott L Whittenburg
Regular nanosized structures are considered to be promising materials for magnetic information storage media with high density of information. Recently attention was paid to static and dynamic magnetic properties arising from dimensional confinement in such nanostructures. Here we present an investigation of permalloy antidot arrays of different thicknesses. Thin permalloy films of thickness ranging from 10 to 500 nm were deposited on anoporous Al2O3 membranes with a pore size of 100 nm. It was found that additional ferromagnetic resonance peaks appear for film thicknesses below 100 nm, while films with larger thicknesses show resonance properties similar to continuous films. A …
Erratum: A Comparison Of The Rough Sphere Rotational Diffusion Model With Experimental Results For Liquid Methyl Iodide, Scott Whittenburg
Erratum: A Comparison Of The Rough Sphere Rotational Diffusion Model With Experimental Results For Liquid Methyl Iodide, Scott Whittenburg
Scott L Whittenburg
No abstract provided.
Thickness Dependence Of Magneto-Transport In Cu-Co Granular Thin Films, Scott Whittenburg
Thickness Dependence Of Magneto-Transport In Cu-Co Granular Thin Films, Scott Whittenburg
Scott L Whittenburg
This work explores the thickness dependence of magneto-transport properties in Cu80Co20 granular thin films with different thickness. These results are compared with silver-based film series studied earlier. It was observed that the thickness dependence of the GMR effect was sensitive to the surface chemistry of the films. The extraordinary Hall effect (EHE) in these films was measured and found to be different from the Ag-based system. In the Cu-based system, the EHE is a weak function of film thickness over the range studied. When the variation of the spontaneous magnetization is taken into account the effective EHE has a universal …
Visual Test Using Color Frequency Doubling, Scott Whittenburg
Visual Test Using Color Frequency Doubling, Scott Whittenburg
Scott L Whittenburg
A novel psychophysical visual test is proposed for testing a person for glaucoma, and based on the discovery that a frequency doubling phenomenon is produced by isoluminent color visual stimuli. More specifically, it is proposed to construct a visual stimulus for which alternating colors in a grating pattern is the only basis for producing the frequency doubling phenomenon. That is, the colors are of the same luminance or intensity level, i.e., isoluminent, but each grating or pattern alternates from one color to another. Preferably, the colors are complementary color pairs, such as blue and yellow.
Micromagnetics Simulation Of Deep-Submicron Supermalloy Disks, Scott Whittenburg
Micromagnetics Simulation Of Deep-Submicron Supermalloy Disks, Scott Whittenburg
Scott L Whittenburg
The results of recent micromagnetic simulations of deep submicron supermalloy disks are presented. A recent experimental measurement of the hysteresis and magnetic domain structure in supermalloy disks with diameters ranging from 55 to 500 nm and thickness ranging from 6 to 15 nm has been reported. Our micromagnetic simulations show remarkable agreement with the experimental hysteresis loops. The simulation results show that for thin or small diameter disks a single magnetic domain exists with all spins aligned. The hysteresis loop represents free rotation of these spins. For larger diameter disks or as the thickness increases the hysteresis loops change shape …
Erratum: Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott Whittenburg
Erratum: Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott Whittenburg
Scott L Whittenburg
No abstract provided.
Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott Whittenburg
Light Scattering Studies Of Transverse Sound Wave And Molecular Motion In Benzonitrile, Scott Whittenburg
Scott L Whittenburg
The zero-frequency shear wave dip appearing in the depolarized Rayleigh spectrum in benzonitrile has been studied as a function of concentration and temperature. The solution study was carried out at constant viscosity equal to the viscosity of liquid benzonitrile at each temperature. The result indicates that the presence of shear wave fine structure does not depend on the collective orientational fluctuations. The orientational and vibrational relaxation times of benzonitrile were measured at various concentrations and temperatures. The orientational relaxation times show no concentration dependence at any temperature, suggesting that the pair correlation is negligible at all concentrations. The orientational relaxation …
Thickness Dependence Of Magnetic Blocking In Granular Thin Films, Scott Whittenburg
Thickness Dependence Of Magnetic Blocking In Granular Thin Films, Scott Whittenburg
Scott L Whittenburg
Interparticle interaction among single domain nanosize magnetic particles embedded in nonmagnetic matrix was studied. Attention was paid to concentrated Cu–Co granular thin films with a fixed magnetic volume fraction 20%. By analyzing theoretical models and comparing with experimental results, a dimensional constraint on the magnetic properties was found. As the film thickness reduces toward the thin limit the interparticle interaction plays important roles in modifying the magnetic behavior. The dipolar interaction energy was calculated among magnetic particles including far-neighbor interaction for films with different thickness values. When magnetization variation is included in the calculation, the resulting calculated interaction energy versus …
Monte Carlo Simulation On The Indirect Exchange Interactions Of Co-Doped Zno Film, Scott Whittenburg
Monte Carlo Simulation On The Indirect Exchange Interactions Of Co-Doped Zno Film, Scott Whittenburg
Scott L Whittenburg
Monte Carlo simulations using a three-dimensional lattice model studied the Ruderman–Kittel–Kasuya–Yosida (RKKY) indirect exchange interaction of doped magnetic Co ions in ZnO films. The results of the calculations show that the RKKY interaction in Co-doped ZnO is long ranged and its magnitude is proportional to R−1 (inverse of the distance R from a central Co2+ ion). The sign oscillates with a frequency that depends on the concentration of the carrier. The long-distance sum of the RKKY indirect exchange energies is positive indicating that these materials are ferromagnetic, in direct correlation with previously reported results
Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, Jin-Seung Jung
Microwave Absorption Of Patterned Arrays Of Nanosized Magnetic Stripes With Different Aspect Ratios, Leszek M. Malkinski, Minghui Yu, Andriy Y. Voyk, Donald J. Scherer Ii, Leonard Spinu, Weillie Zhou, Scott Whittenburg, Zachary Davis, Jin-Seung Jung
Scott L Whittenburg
Arrays consisting of nanosized stripes of Permalloy with different length-to-width ratios have been fabricated using electron beam nanolithography, magnetron sputtering, and lift-off process. These stripes have a thickness of 100 nm, a width of 300 nm, and different lengths ranging from 300 nm to 100 μm. The stripes are separated by a distance of 1 μm. Magnetization hysteresis loops were measured using a superconducting quantum interference device susceptometer. Microwave absorption at 9.8 GHz was determined by means of ferromagnetic resonance technique. The dependence of the resonant field on the angle between the nanostructure and the in-plane dc magnetic field indicates …