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Full-Text Articles in Physics
Double Resonance Spectroscopy Of The D1Πu+ And B''B-Bar 1Σu+ States Near The Third Dissociation Threshold Of H2, R. C. Ekey, A. E. Cordova, W. Duan, Alexander M. Chartrand, Elizabeth Mccormack
Double Resonance Spectroscopy Of The D1Πu+ And B''B-Bar 1Σu+ States Near The Third Dissociation Threshold Of H2, R. C. Ekey, A. E. Cordova, W. Duan, Alexander M. Chartrand, Elizabeth Mccormack
Physics Faculty Research and Scholarship
Double-resonance laser spectroscopy via the E, F 1Σg+, v' = 6, J' state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14–17 levels of the D1Πu+ state of H2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al. 2010 J. Chem. Phys. 133 144317) and fully ab …
Room-Temperature Multiferroic Hexagonal Lufeo3 Films, Wenbin Wang, Jun Zhao, Wenbo Wang, Zheng Gai, Nina Balke, Miaofang Chi, Ho Nyung Lee, Wei Tian, Leyi Zhu, Xuemei Cheng, David J. Keavney, Jieyu Yi, Thomas Z. Ward, Paul C. Snijders, Hans M. Christen, Weida Wu, Jian Shen, Xiaoshan Xu
Room-Temperature Multiferroic Hexagonal Lufeo3 Films, Wenbin Wang, Jun Zhao, Wenbo Wang, Zheng Gai, Nina Balke, Miaofang Chi, Ho Nyung Lee, Wei Tian, Leyi Zhu, Xuemei Cheng, David J. Keavney, Jieyu Yi, Thomas Z. Ward, Paul C. Snijders, Hans M. Christen, Weida Wu, Jian Shen, Xiaoshan Xu
Physics Faculty Research and Scholarship
The crystal and magnetic structures of single-crystalline hexagonal LuFeO3 films have been studied using x-ray, electron, and neutron diffraction methods. The polar structure of these films are found to persist up to 1050 K; and the switchability of the polar behavior is observed at room temperature, indicating ferroelectricity. An antiferromagnetic order was shown to occur below 440 K, followed by a spin reorientation resulting in a weak ferromagnetic order below 130 K. This observation of coexisting multiple ferroic orders demonstrates that hexagonal LuFeO3 films are room-temperature multiferroics.
Tuning Vortex Confinement By Magnetic Domains In A Superconductor/Ferromagnet Bilayer, Marta Z. Cieplak, Z. Adamus, M. Kończykowski, L. Y. Zhu, Xuemei Cheng, C. L. Chien
Tuning Vortex Confinement By Magnetic Domains In A Superconductor/Ferromagnet Bilayer, Marta Z. Cieplak, Z. Adamus, M. Kończykowski, L. Y. Zhu, Xuemei Cheng, C. L. Chien
Physics Faculty Research and Scholarship
We use a line of miniature Hall sensors to study the effect of magnetic-domain-induced vortex confinement on the flux dynamics in a superconductor/ferromagnet bilayer. A single tunable bilayer is built of a ferromagnetic Co/Pt multilayer with perpendicular magnetic anisotropy and a superconducting Nb layer, with the insulating layer in-between to avoid the proximity effect. The magnetic-domain patterns of various geometries are reversibly predefined in the Co/Pt multilayer using the appropriate magnetization procedure. The magnetic-domain geometry strongly affects vortex dynamics, leading to geometry-dependent trapping of vortices at the sample edge, nonuniform flux penetration, and strongly nonuniform critical current density. With the …
Pt Magnetic Polarization On Y3Fe5O12 And Magnetotransport Characteristics, Y. M. Lu, Y. Choi, C. M. Ortega, Xuemei Cheng, J. W. Cai, S. Y. Huang, L. Sun, C. L. Chien
Pt Magnetic Polarization On Y3Fe5O12 And Magnetotransport Characteristics, Y. M. Lu, Y. Choi, C. M. Ortega, Xuemei Cheng, J. W. Cai, S. Y. Huang, L. Sun, C. L. Chien
Physics Faculty Research and Scholarship
Thin Pt films on an yttrium iron garnet (YIG=Y3Fe5O12) show ferromagneticlike transport properties, which may impact the functionality of Pt in spin current detection, but do not provide direct quantitative information on the Pt magnetization. We report magnetic x-ray magnetic circular dichroism measurements of YIG/Pt(1.5 nm) showing an average Pt moment of 0.054 μB at 300 K and 0.076 μB at 20 K. This observation indicates strong proximity effects and induced magnetic ordering in Pt on magnetic insulators and their contribution to the spin-related measurements should not be neglected. The transport characteristics …
Turbulence And Transport Suppression Scaling With Flow Shear On The Large Plasma Device, David A. Schaffner, T. A. Carter, G. D. Rossi, D. S. Guice, J. E. Maggs, S. Vincena, B. Friedman
Turbulence And Transport Suppression Scaling With Flow Shear On The Large Plasma Device, David A. Schaffner, T. A. Carter, G. D. Rossi, D. S. Guice, J. E. Maggs, S. Vincena, B. Friedman
Physics Faculty Research and Scholarship
Continuous control over azimuthal flow and shear in the edge of the Large Plasma Device (LAPD) [W. Gekelman et al., Rev. Sci. Instr. 62, 2875 (1991)] has been achieved using a biasable limiter. This flow control has allowed a careful study of the effect of flow shear on pressure-gradient-driven turbulence and particle transport in LAPD. The combination of externally controllable shear in a turbulent plasma along with the detailed spatial diagnostic capabilities on LAPD makes the experiment a useful testbed for validation of shear suppression models. Motivated by these models, power-law fits are made to the density and radial velocity …
Nonlinear Instability In Simulations Of Large Plasma Device Turbulence, B. Friedman, T. A. Carter, M. V. Umansky, David A. Schaffner, I. Joseph
Nonlinear Instability In Simulations Of Large Plasma Device Turbulence, B. Friedman, T. A. Carter, M. V. Umansky, David A. Schaffner, I. Joseph
Physics Faculty Research and Scholarship
Several simulations of turbulence in the Large Plasma Device (LAPD) [Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)] are energetically analyzed and compared with each other and with the experiment. The simulations use the same model, but different axial boundary conditions. They employ either periodic, zero-value, zero-derivative, or sheath axial boundaries. The linear stability physics is different between the scenarios because the various boundary conditions allow the drift wave instability to access different axial structures, and the sheath boundary simulation contains a conducting wall mode instability which is just as unstable as the drift waves. Nevertheless, the turbulence in …