Magnetic single-domain islands based on in-plane anisotropy （usually, shape anisotropy） and their dipole-dipole interactions have been investigated extensively in recent years. This has been driven by potential appl...Magnetic single-domain islands based on in-plane anisotropy （usually, shape anisotropy） and their dipole-dipole interactions have been investigated extensively in recent years. This has been driven by potential applications in magnetic recording, spintronics, magneto-biology, etc. Here, we propose a concept of out- of-plane magnetic dusters with configurable domain structures （multi-flux states） via dipole-dipole interactions. Their flux stages can be switched through an external magnetic field. The concept has been successfully demonstrated by patterned [Co/Pd] islands. A [Co/Pd] multilayer exhibits a large perpendicular anisotropy, a strong physical separation, and uniform intrinsic properties after being patterned into individual islands by electron beam lithography. A three- island cluster with six stable flux states has been realized by optimizing island size, thickness, gap, anisotropy, saturation magnetization, etc. Using [Co/Pd] multilayers, we have optimized the island structure by tuning magnetic properties （saturation magnetization and perpendicular anisotropy） using Landau-Liftshitz- Gilbert （LLG） simulation/calculation. Potential applications have been proposed, including a flexi-programmable logic device with AND, OR, NAND, and NOR functionalities and a magnetic domino, which can propagate magnetic current as far as 1 μm down from the surface via vertical dipole-dipole interactions.展开更多
The article presents the results of experimental studies of the physical mechanisms and magnetic switching dynamics of films with one or two magnetic nanolayers under an irradiation picosecond and femtosecond laser pu...The article presents the results of experimental studies of the physical mechanisms and magnetic switching dynamics of films with one or two magnetic nanolayers under an irradiation picosecond and femtosecond laser pulses and also the samples of data recording devices on the spin storage medium are described. The study used a film with perpendicular anisotropy （Tb22Co5Fe73/Pr6O11/Tb29Co5Fe76, Tb25Co5Fe70/Al2O3, Tb22Co5Fe73, Tb19Co5Fe76） and films planar single-axis magnetic anisotropy （Co80Fe20/Pr6O11/CO30Fe70）. The magnetic switching of magnetic layers under action the magnetic field of a spin current is the most important for practical use in elements of spintronic. The spin current can also be realized using short electrical pulses. On the basis of this mechanism, the high-speed recording of information on the spin carrier has been realized.展开更多
Co/Pt multilayers with perpendicular anisotropy were deposited using a dc magnetron sputtering system under high vacuum.Magnetization process was investigated by the measurement of magnetic components parallel and per...Co/Pt multilayers with perpendicular anisotropy were deposited using a dc magnetron sputtering system under high vacuum.Magnetization process was investigated by the measurement of magnetic components parallel and perpendicular to the applied field.A dependence of the coercivity of Co/Pt multilayers on the Co layer thickness was reported,in which the total thickness of Co layers kept constant.It is observed that the coercivity increases with the increment of Co layer thickness.For the samples with the same Co layer thickness while different total Co layer thickness,the coercivity first increases and then decreases with the increase of the total thickness of Co layers.This effect could be attributed to the competition between the reduction of HC related to incoherent reversal and the step-up of HC contributed by the magnetic polarization of Pt atoms at the interface of Co and Pt layers during magnetization reversal.The results show that the change of the coercivity is strongly related to the Co layer thickness,but not the total thickness of Co layers.The dependence of the coercivity on the angle between an applied field and the easy axis shows that the nucleation mode is dominant in magnetization reversal process of the samples.展开更多
The S wave velocity structure between the hypocenter of C060394F earthquake,South Java and a series of observatory stations located in Australia and South-East Asia have been investigated through seismogram analysis i...The S wave velocity structure between the hypocenter of C060394F earthquake,South Java and a series of observatory stations located in Australia and South-East Asia have been investigated through seismogram analysis in the time domain and the three Cartesian components.The synthetic seismogram is constructed from the PREMAN global earth model.Seismogram comparison between the measured and synthetic seismograms shows large discrepancies.A correction to the S wave velocity structure is needed to solve these discrepancies.Seismogram analysis and fitting at the observatory stations located in Australia show a positive anomaly,whereas the stations in South-East Asia show a strong negative anomaly.Vertical anisotropy occurred in the upper mantle layer and earth mantle layers beneath it.The seismogram analysis in the time domain and the three components simultaneously provides a better picture of the earth model,compared to the analysis of the seismogram with arrival time,travel time difference and dispersion analysis.展开更多
文摘Magnetic single-domain islands based on in-plane anisotropy （usually, shape anisotropy） and their dipole-dipole interactions have been investigated extensively in recent years. This has been driven by potential applications in magnetic recording, spintronics, magneto-biology, etc. Here, we propose a concept of out- of-plane magnetic dusters with configurable domain structures （multi-flux states） via dipole-dipole interactions. Their flux stages can be switched through an external magnetic field. The concept has been successfully demonstrated by patterned [Co/Pd] islands. A [Co/Pd] multilayer exhibits a large perpendicular anisotropy, a strong physical separation, and uniform intrinsic properties after being patterned into individual islands by electron beam lithography. A three- island cluster with six stable flux states has been realized by optimizing island size, thickness, gap, anisotropy, saturation magnetization, etc. Using [Co/Pd] multilayers, we have optimized the island structure by tuning magnetic properties （saturation magnetization and perpendicular anisotropy） using Landau-Liftshitz- Gilbert （LLG） simulation/calculation. Potential applications have been proposed, including a flexi-programmable logic device with AND, OR, NAND, and NOR functionalities and a magnetic domino, which can propagate magnetic current as far as 1 μm down from the surface via vertical dipole-dipole interactions.
文摘The article presents the results of experimental studies of the physical mechanisms and magnetic switching dynamics of films with one or two magnetic nanolayers under an irradiation picosecond and femtosecond laser pulses and also the samples of data recording devices on the spin storage medium are described. The study used a film with perpendicular anisotropy （Tb22Co5Fe73/Pr6O11/Tb29Co5Fe76, Tb25Co5Fe70/Al2O3, Tb22Co5Fe73, Tb19Co5Fe76） and films planar single-axis magnetic anisotropy （Co80Fe20/Pr6O11/CO30Fe70）. The magnetic switching of magnetic layers under action the magnetic field of a spin current is the most important for practical use in elements of spintronic. The spin current can also be realized using short electrical pulses. On the basis of this mechanism, the high-speed recording of information on the spin carrier has been realized.
基金Projects(10574065,20833002) supported by the National Natural Science Foundation of ChinaProject(2009CB929503) supported by the National Basic Research Program of China
文摘Co/Pt multilayers with perpendicular anisotropy were deposited using a dc magnetron sputtering system under high vacuum.Magnetization process was investigated by the measurement of magnetic components parallel and perpendicular to the applied field.A dependence of the coercivity of Co/Pt multilayers on the Co layer thickness was reported,in which the total thickness of Co layers kept constant.It is observed that the coercivity increases with the increment of Co layer thickness.For the samples with the same Co layer thickness while different total Co layer thickness,the coercivity first increases and then decreases with the increase of the total thickness of Co layers.This effect could be attributed to the competition between the reduction of HC related to incoherent reversal and the step-up of HC contributed by the magnetic polarization of Pt atoms at the interface of Co and Pt layers during magnetization reversal.The results show that the change of the coercivity is strongly related to the Co layer thickness,but not the total thickness of Co layers.The dependence of the coercivity on the angle between an applied field and the easy axis shows that the nucleation mode is dominant in magnetization reversal process of the samples.
文摘The S wave velocity structure between the hypocenter of C060394F earthquake,South Java and a series of observatory stations located in Australia and South-East Asia have been investigated through seismogram analysis in the time domain and the three Cartesian components.The synthetic seismogram is constructed from the PREMAN global earth model.Seismogram comparison between the measured and synthetic seismograms shows large discrepancies.A correction to the S wave velocity structure is needed to solve these discrepancies.Seismogram analysis and fitting at the observatory stations located in Australia show a positive anomaly,whereas the stations in South-East Asia show a strong negative anomaly.Vertical anisotropy occurred in the upper mantle layer and earth mantle layers beneath it.The seismogram analysis in the time domain and the three components simultaneously provides a better picture of the earth model,compared to the analysis of the seismogram with arrival time,travel time difference and dispersion analysis.
