The Experts below are selected from a list of 88230 Experts worldwide ranked by ideXlab platform
A. K. Grover - One of the best experts on this subject based on the ideXlab platform.
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new samarium and neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field
Journal of Physics D, 2009Co-Authors: Prasanna D. Kulkarni, U. V. Vaidya, S. K. Dhar, P Manfrinetti, A. K. GroverAbstract:Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near-zero net magnetization with substitutions of 6?9?atomic % of Nd and 25?atomic % of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of 'zero magnetization' axis at low magnetic fields (<103?Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with 'no-net' magnetization and appreciable conduction Electron Polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of ~270?K underscore the importance of these materials for potential applications in spintronics.
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new samarium and neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field
arXiv: Strongly Correlated Electrons, 2008Co-Authors: Prasanna D. Kulkarni, U. V. Vaidya, S. K. Dhar, P Manfrinetti, A. K. GroverAbstract:Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25 atomic percent of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of zero magnetization axis at low magnetic fields (less than 103 Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with no net magnetization and appreciable conduction Electron Polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of about 270 K, underscore the importance of these materials for potential applications in spintronics.
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Repeated magnetic compensation behavior in the rare-earth alloy Nd 0.75 Gd 0.25 Rh 3 B 2 with hexagonal structure and planar anisotropy
Physical Review B, 2008Co-Authors: Prasanna D. Kulkarni, U. V. Vaidya, V. C. Rakhecha, A. Thamizhavel, S. K. Dhar, A. K. Nigam, S. Ramakrishnan, A. K. GroverAbstract:The results of dc and ac magnetization, electrical resistance, and heat-capacity studies in an admixed rare-earth alloy ${\text{Nd}}_{0.75}{\text{Gd}}_{0.25}{\text{Rh}}_{3}{\text{B}}_{2}$, which is close to the zero magnetization limit, are reported. Interesting observations include the two antiferromagneticlike transitions, concomitant repeated/multiple magnetic compensation behavior, and a characteristic oscillatory magnetic response, with temperature dependence of magnetization at low fields crossing the $M=0$ axis thrice. The effective coercive field relating to the residual remanence also has an oscillatory response, with two minima located close to two ``zero-cross over'' temperatures. The unusual behavior in ${\text{Nd}}_{0.75}{\text{Gd}}_{0.25}{\text{Rh}}_{3}{\text{B}}_{2}$ is conjectured to arise from its anisotropic hexagonal structure, with planar anisotropy, resulting in a quasi-one-dimensional Electronic structure and the accentuated role of conduction-Electron Polarization near the zero magnetization limit.
Christoph H Keitel - One of the best experts on this subject based on the ideXlab platform.
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polarized ultrashort brilliant multi gev γ rays via single shot laser Electron interaction
Physical Review Letters, 2020Co-Authors: Rashid Shaisultanov, Yueyue Chen, Feng Wan, Karen Zaven Hatsagortsyan, Christoph H KeitelAbstract:Generation of circularly polarized (CP) and linearly polarized (LP) $\ensuremath{\gamma}$ rays via the single-shot interaction of an ultraintense laser pulse with a spin-polarized counterpropagating ultrarelativistic Electron beam has been investigated in nonlinear Compton scattering in the quantum radiation-dominated regime. For the process simulation, a Monte Carlo method is developed which employs the Electron-spin-resolved probabilities for polarized photon emissions. We show efficient ways for the transfer of the Electron Polarization to the high-energy photon Polarization. In particular, multi-GeV CP (LP) $\ensuremath{\gamma}$ rays with Polarization of up to about 95% can be generated by a longitudinally (transversely) spin-polarized Electron beam, with a photon flux meeting the requirements of recent proposals for the vacuum birefringence measurement in ultrastrong laser fields. Such high-energy, high-brilliance, high-Polarization $\ensuremath{\gamma}$ rays are also beneficial for other applications in high-energy physics, and laboratory astrophysics.
C Rettori - One of the best experts on this subject based on the ideXlab platform.
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conduction Electrons in aperiodic versus periodic structures an esr study of quasicrystalline i y gd cd and its approximant y gd cd 6
Physical Review B, 2019Co-Authors: M Cabrerabaez, M A Avila, C RettoriAbstract:A formal description of collective Electronic states in condensed-matter systems lacking long-range periodicity remains a theoretical challenge. To experimentally explore the differences in Electronic and magnetic behavior between metallic quasicrystals (QCs) and their conventional crystalline analogs [quasicrystal approximants (QCAs)], we have grown single crystals of ${\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{Gd}}_{x}{\mathrm{Cd}}_{6}$ (QCA) together with their QC counterparts $i\text{\ensuremath{-}}{\mathrm{Y}}_{1\ensuremath{-}x}{\mathrm{Gd}}_{x}\text{\ensuremath{-}}\mathrm{Cd}$ for $x=0.006$, 0.01, 0.1, and 1.00, and we carried out comparative $T$-dependent Electron spin resonance (ESR) measurements. On the high Gd concentration side, $x=1.00$, we confirm that ${\mathrm{GdCd}}_{6}$ adopts an antiferromagnetic ground state below ${T}_{N}\ensuremath{\sim}22\phantom{\rule{4pt}{0ex}}\mathrm{K}$, whereas $i$-Gd-Cd presents spin-glass-like behavior showing similar local and dynamical properties from the point of view of ESR. For the diluted samples, our ESR experimental results show similar local conduction Electron Polarization behavior at the ${\mathrm{Gd}}^{3+}$ site in all QC/QCA pairs investigated, supporting the validity of using QCAs as periodic representations of QCs in terms of short-range Electronic interactions. However, there is a measurable difference in the Korringa relaxation rate (spin-flip relaxation process between the localized ${\mathrm{Gd}}^{3+}4f$ Electron and the delocalized $s$-type conduction Electrons at the Fermi surface) between the QC/QCA pairs probably associated with the lack of periodicity. We expect that our comparative ESR study may provide support and motivation for the development of new theoretical approaches toward a generalized band-structure theory, contemplating condensed-matter systems beyond the scope of traditional periodicity.
Feng Wan - One of the best experts on this subject based on the ideXlab platform.
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polarized ultrashort brilliant multi gev γ rays via single shot laser Electron interaction
Physical Review Letters, 2020Co-Authors: Rashid Shaisultanov, Yueyue Chen, Feng Wan, Karen Zaven Hatsagortsyan, Christoph H KeitelAbstract:Generation of circularly polarized (CP) and linearly polarized (LP) $\ensuremath{\gamma}$ rays via the single-shot interaction of an ultraintense laser pulse with a spin-polarized counterpropagating ultrarelativistic Electron beam has been investigated in nonlinear Compton scattering in the quantum radiation-dominated regime. For the process simulation, a Monte Carlo method is developed which employs the Electron-spin-resolved probabilities for polarized photon emissions. We show efficient ways for the transfer of the Electron Polarization to the high-energy photon Polarization. In particular, multi-GeV CP (LP) $\ensuremath{\gamma}$ rays with Polarization of up to about 95% can be generated by a longitudinally (transversely) spin-polarized Electron beam, with a photon flux meeting the requirements of recent proposals for the vacuum birefringence measurement in ultrastrong laser fields. Such high-energy, high-brilliance, high-Polarization $\ensuremath{\gamma}$ rays are also beneficial for other applications in high-energy physics, and laboratory astrophysics.
Prasanna D. Kulkarni - One of the best experts on this subject based on the ideXlab platform.
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new samarium and neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field
Journal of Physics D, 2009Co-Authors: Prasanna D. Kulkarni, U. V. Vaidya, S. K. Dhar, P Manfrinetti, A. K. GroverAbstract:Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near-zero net magnetization with substitutions of 6?9?atomic % of Nd and 25?atomic % of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of 'zero magnetization' axis at low magnetic fields (<103?Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with 'no-net' magnetization and appreciable conduction Electron Polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of ~270?K underscore the importance of these materials for potential applications in spintronics.
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new samarium and neodymium based admixed ferromagnets with near zero net magnetization and tunable exchange bias field
arXiv: Strongly Correlated Electrons, 2008Co-Authors: Prasanna D. Kulkarni, U. V. Vaidya, S. K. Dhar, P Manfrinetti, A. K. GroverAbstract:Rare earth based intermetallics, SmScGe and NdScGe, are shown to exhibit near zero net magnetization with substitutions of 6 to 9 atomic percent of Nd and 25 atomic percent of Gd, respectively. The notion of magnetic compensation in them is also elucidated by the crossover of zero magnetization axis at low magnetic fields (less than 103 Oe) and field-induced reversal in the orientation of the magnetic moments of the dissimilar rare earth ions at higher magnetic fields. These magnetically ordered materials with no net magnetization and appreciable conduction Electron Polarization display an attribute of an exchange bias field, which can be tuned. The attractively high magnetic ordering temperatures of about 270 K, underscore the importance of these materials for potential applications in spintronics.
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Repeated magnetic compensation behavior in the rare-earth alloy Nd 0.75 Gd 0.25 Rh 3 B 2 with hexagonal structure and planar anisotropy
Physical Review B, 2008Co-Authors: Prasanna D. Kulkarni, U. V. Vaidya, V. C. Rakhecha, A. Thamizhavel, S. K. Dhar, A. K. Nigam, S. Ramakrishnan, A. K. GroverAbstract:The results of dc and ac magnetization, electrical resistance, and heat-capacity studies in an admixed rare-earth alloy ${\text{Nd}}_{0.75}{\text{Gd}}_{0.25}{\text{Rh}}_{3}{\text{B}}_{2}$, which is close to the zero magnetization limit, are reported. Interesting observations include the two antiferromagneticlike transitions, concomitant repeated/multiple magnetic compensation behavior, and a characteristic oscillatory magnetic response, with temperature dependence of magnetization at low fields crossing the $M=0$ axis thrice. The effective coercive field relating to the residual remanence also has an oscillatory response, with two minima located close to two ``zero-cross over'' temperatures. The unusual behavior in ${\text{Nd}}_{0.75}{\text{Gd}}_{0.25}{\text{Rh}}_{3}{\text{B}}_{2}$ is conjectured to arise from its anisotropic hexagonal structure, with planar anisotropy, resulting in a quasi-one-dimensional Electronic structure and the accentuated role of conduction-Electron Polarization near the zero magnetization limit.