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Full-Text Articles in Physical Sciences and Mathematics
Ferroelectric-Field-Induced Tuning Of Magnetism In The Colossal Magnetoresistive Oxide La1Àxsrxmno3, X. Hong, A. Posadas, A. Lin, C. H. Ahn
Ferroelectric-Field-Induced Tuning Of Magnetism In The Colossal Magnetoresistive Oxide La1Àxsrxmno3, X. Hong, A. Posadas, A. Lin, C. H. Ahn
Xia Hong Publications
A ferroelectric field effect approach is presented for modulating magnetism in the colossal magnetoresistive oxide La1-xSrxMnO3 (LSMO). The ferromagnetic Curie temperature of ultrathin LSMO films was shifted by 35 K reversibly using the polarization field of the ferroelectric oxide Pb(ZrxTi1-x)O3 in a field effect structure. This shift was also observed in magnetoresistance measurements, with the maximum magnetoresistance ratio at 6 T increasing from 64% to 77%. This model system approach does not introduce substitutional disorder or structural distortion, demonstrating that regulating the carrier concentration alone changes the magnetic phase transition …
An Optical Trap For Relativistic Plasma, Ping Zhang, Ned Saleh, Shouyuan Chen, Zhengming Sheng, Donald Umstadter
An Optical Trap For Relativistic Plasma, Ping Zhang, Ned Saleh, Shouyuan Chen, Zhengming Sheng, Donald Umstadter
Donald Umstadter Publications
The first optical trap capable of confining relativistic electrons, with kinetic energy <350 keV was created by the interference of spatially and temporally overlapping terawatt power, 400 fs duration laser pulses (<2.4x1018 W/cm2) in plasma. Analysis and computer simulation predicted that the plasma density was greatly modulated, reaching a peak density up to 10 times the background density (ne /n0;10) at the interference minima. Associated with this charge displacement, a direct-current electrostatic field of strength of ~2 x 1011 eV/m was excited. These predictions were confirmed experimentally by Thomson and Raman scattering diagnostics. Also confirmed were predictions that the electron density grating acted as a multi-layer mirror to transfer energy between the crossed laser beams, resulting …
Ferroelectricity In Free Niobium Clusters, Ramiro Moro, Xiaoshan Xu, Shuangye Yin, Walt A. De Heer
Ferroelectricity In Free Niobium Clusters, Ramiro Moro, Xiaoshan Xu, Shuangye Yin, Walt A. De Heer
Xiaoshan Xu Papers
Electric deflections of gas-phase, cryogenically cooled, neutral niobium clusters [NbN; number of atoms (N) = 2 to 150, temperature (T) = 20 to 300 kelvin], measured in molecular beams, show that cold clusters may attain an anomalous component with very large electric dipole moments. In contrast, room-temperature measurements show normal metallic polarizabilities. Characteristic energies kBTG(N) [Boltzmann constant kB times a transition temperature TG(N)] are identified, below which the ferroelectric-like state develops. Generally, TG decreases [110 > TG(N) > 10K] as …
An Experimental And Theoretical Study Of Transient Negative Ions In Mg, Zn, Cd And Hg, J. P. Sullivan, Paul Burrow, D. S. Newman, K. Bartschat, J. A. Michejda, P. Panajotovic, M. Moghbelalhossein, R. P. Mceachran, Stephen J. Busckman
An Experimental And Theoretical Study Of Transient Negative Ions In Mg, Zn, Cd And Hg, J. P. Sullivan, Paul Burrow, D. S. Newman, K. Bartschat, J. A. Michejda, P. Panajotovic, M. Moghbelalhossein, R. P. Mceachran, Stephen J. Busckman
Paul Burrow Publications
A range of experimental and theoretical techniques have been applied to the study of transient negative ions (resonances) formed in electron scattering from the Group II metals Mg, Zn, Cd, and Hg at incident electron energies below the first ionization potential. A wealth of resonance structures have been observed and from the experimental observations and theoretical information, classifications are proposed for some of these negative ion states.