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Full-Text Articles in Physics

Synthesis Of Mild–Hard Aao Templates For Studying Magnetic Interactions Between Metal Nanowires, Jin-Hee Lim, Aurelian Rotaru, Seong-Gi Min, Leszek Malkinski, John B. Wiley Nov 2010

Synthesis Of Mild–Hard Aao Templates For Studying Magnetic Interactions Between Metal Nanowires, Jin-Hee Lim, Aurelian Rotaru, Seong-Gi Min, Leszek Malkinski, John B. Wiley

Physics Faculty Publications

The sequential application of mild and hard anodization techniques in the fabrication of porous aluminamembranes allows one to decrease the number of continuous pores in anodized aluminium oxide (AAO) templates. Initially, standard mild anodization techniques were used to create porous templates with 100 nm interpore distances and 70 nm pore diameters. Hard anodization treatment on the same membrane then produced interpore distances of about 265 nm with diameters of 110 nm. At the interface between the two anodization steps, many of the mild-side pores were terminated to create a mild–hard membrane (Mi–Ha AAO) where the functional interpore distances were 200–300 …


Transmission Of P- And S-Polarized Light Through A Prism And The Condition Of Minimum Deviation, R. M.A. Azzam, Ryan M. Adams Aug 2010

Transmission Of P- And S-Polarized Light Through A Prism And The Condition Of Minimum Deviation, R. M.A. Azzam, Ryan M. Adams

Electrical Engineering Faculty Publications

The condition of minimum deviation (MD) by a transparent optically isotropic prism is re-derived, and expressions for the intensity transmittances Tp(θ) and Ts(θ) of an uncoated prism of refractive index n and prism angle α for incident p- ands-polarized light and their derivatives with respect to the internal angle of refraction θ are obtained. When the MD condition(θ=α/2) is satisfied, Ts is maximum and Tp is maximum or minimum. The transmission ellipsometric parametersψt,Δt of a symmetrically coated prism are also shown to be locally stationary with respect to θ at θ=α/2 . The constraint on (n,α) for …


Difference Between The Second-Brewster And Pseudo-Brewster Angles When Polarized Light Is Reflected At A Dielectric–Conductor Interface, A. Alsamman, R. M.A. Azzam Apr 2010

Difference Between The Second-Brewster And Pseudo-Brewster Angles When Polarized Light Is Reflected At A Dielectric–Conductor Interface, A. Alsamman, R. M.A. Azzam

Electrical Engineering Faculty Publications

For a given pseudo-Brewster angle ϕpB of minimum reflectance ∣∣rp∣∣ of p-polarized light at a dielectric-conductor interface, the second-Brewster angle ϕ2B of minimum reflectance ratio |ρ|=∣∣rp∣∣/|rs| of the p and s polarizations is determined for all possible values of the complex relative dielectric function ϵ that lead to the same ϕpB . The difference ϕ2B−ϕpB is considered as a function of ϕpB and θ=arg(ϵ) . For any given ϕpB , the difference ϕ2B−ϕpB=0 atθ=0(ϵr>0,ϵi=0) increases monotonically as a function of θ and reaches maximum value {ϕ2B−ϕpB}max in the limit as θ→180° (ϵr<0,ϵi=0) . This maximum difference {ϕ2B−ϕpB}max has an upper limit of 15.701° whenϕpB=28.195° .


Interplay Between The Lattice And Spin Degrees Of Freedom In (Sr1−Xcax)3ru2o7, Jin Peng, David Fobes, Tijian Liu, Xiaoshan Wu, H M. Pham, Leonard Spinu, Z Q. Mao Jan 2010

Interplay Between The Lattice And Spin Degrees Of Freedom In (Sr1−Xcax)3ru2o7, Jin Peng, David Fobes, Tijian Liu, Xiaoshan Wu, H M. Pham, Leonard Spinu, Z Q. Mao

Physics Faculty Publications

The Sr1−xCax3Ru2O7 solid solution series exhibits complex magnetic ground states, ranging from an itinerant metamagnetic state, to a quasi-two-dimensional 2D heavy-mass nearly ferromagneticFM state, and finally to a long-range antiferromagnetically ordered state Z. Qu et al. Phys. Rev. B. 78, R180407 2008. In this paper, we investigate the evolution of structural distortion and magnetic anisotropy with Ca content in this material system. Our results show that both the magnetic phase transitions and magnetic anistropy of this system couple with the evolution of structure distortion. The transformation from the itinerant metamagnetic to the nearly ferromagnetic state is accompanied …


Fabrication And Magnetic Properties Of Fe Nanostructures In Anodic Alumina Membrane, J H. Lim, W S. Chae, H O. Lee, L Malkinski, S G. Min, J B. Wiley, J H. Jun, S H. Lee, J S. Jung Jan 2010

Fabrication And Magnetic Properties Of Fe Nanostructures In Anodic Alumina Membrane, J H. Lim, W S. Chae, H O. Lee, L Malkinski, S G. Min, J B. Wiley, J H. Jun, S H. Lee, J S. Jung

Physics Faculty Publications

Several Fe nanostructures with different lengths, diameters, and separations of the constituting magnetic components have been synthesized using anodized alumina membranes (AAMs) to understand the influence of these parameters on their magnetic properties. Fe nanostructures with high crystallinity and (110) orientation were synthesized by electrodeposition at room temperature in regular AAMs and mild-hard AAM (Mi-Ha AAM). Fe nanostructures with different aspect ratios (1:1, 1:10, and 1:75) in the form of nanodots, nanorods, or nanowires were synthesized in regular AAMs with the 100 nm interpore distance. Mi-Ha AAMs with two different pore sizes (70 and 120 nm) and 250 nm interpore …


Collinear Phase Matching For Second Harmonic Generation Using Conoscopic Interferometry, A Puri, A De Jan 2010

Collinear Phase Matching For Second Harmonic Generation Using Conoscopic Interferometry, A Puri, A De

Physics Faculty Publications

The problem of finding phase-matching directions in noncentrosymmetric biaxial crystals is simplified here by the use of Conoscopic interferometry. Based on vector relations for wave propagation in birefringent media and solutions to phase-matching equations, we show that phase matching directions can be located on the conoscopic interferograms and that fringe numbers for dark-isochromes can be used as a guide to find phase-matching directions for a biaxial crystal. This technique can be generalized and extended to any anisotropic crystal. We have demonstrated this method for the particular case of a biaxial KTiOPO4 crystal, where it is found to be particularly …