Zinc-ion batteries are promising for large-scale electrochemical energy storage systems,which still suffer from interfacial issues,e.g.,hydrogen evolution side reaction(HER),self-corrosion,and uncontrollable dendritic...Zinc-ion batteries are promising for large-scale electrochemical energy storage systems,which still suffer from interfacial issues,e.g.,hydrogen evolution side reaction(HER),self-corrosion,and uncontrollable dendritic Zn electrodeposition.Although the regulation of electric double layer(EDL)has been verified for interfacial issues,the principle to select the additive as the regulator is still misted.Here,several typical amino acids with different characteristics were examined to reveal the interfacial behaviors in regulated EDL on the Zn anode.Negative charged acidic polarity(NCAP)has been unveiled as the guideline for selecting additive to reconstruct EDL with an inner zincophilic H_(2)O-poor layer and to replace H_(2)O molecules of hydrated Zn^(2+)with NCAP glutamate.Taking the synergistic effects of EDL regulation,the uncontrollable interface is significantly stabilized from the suppressed HER and anti-self-corrosion with uniform electrodeposition.Consequently,by adding NCAP glutamate,a high average Coulombic efficiency of 99.83%of Zn metal is achieved in Zn|Cu asymmetrical cell for over 2000 cycles,and NH4V4O10|Zn full cell exhibits a high-capacity retention of 82.1%after 3000 cycles at 2 A g^(-1).Recapitulating,the NCAP principle posted here can quicken the design of trailblazing electrolyte additives for aqueous Zn-based electrochemical energy storage systems.展开更多
For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors,potassium ions are pre-inserted into MnO2 tunnel structure,the as-prepared K1.04Mn8 O16 materials consist of nanoparticles and nano...For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors,potassium ions are pre-inserted into MnO2 tunnel structure,the as-prepared K1.04Mn8 O16 materials consist of nanoparticles and nanorods were prepared by facile high-temperature solid-state reaction.The as-prepared materials were well studied and they show outstanding electrochemical behavior.We assembled hybrid supercapacitors with commercial activated carbon(YEC-8 A)as anode and K1.04Mn8 O16 as cathode.It shows high energy and power densities.Li-ion capacitors reach a high energy density of 127.61 Wh kg-1 at the power density of 99.86 W kg-1 and Na-ion capacitor obtains 170.96 Wh kg-1 at 133.79 W kg-1.In addition,the hybrid supercapacitors demonstrate excellent cycling performance which maintain 97%capacitance retention for Li-ion capacitor and 85%for Na-ion capacitor after 10,000 cycles.展开更多
We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters fro...We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters from the tunneling magnetoresistance(TMR) vs.field loops and current-driven magnetization switching experiments.Based on the experimental results and device parameters,we further estimate current-driven switching performance of pMTJ including switching time and power,and their dependence on perpendicular magnetic anisotropy and damping constant of the free layer by SPICE-based circuit simulations.Our results show that the pMTJ cells exhibit a less than 1 ns switching time and write energies <1.4 pJ;meanwhile the lower perpendicular magnetic anisotropy(PMA) and damping constant can further reduce the switching time at the studied range of damping constant α <0.1.Additionally,our results demonstrate that the pMTJs with the thermal stability factor■73 can be easily transformed into spin-torque nano-oscillators from magnetic memory as microwave sources or detectors for telecommunication devices.展开更多
Spin Hall nano oscillator(SHNO),a new type spintronic nano-device,can electrically excite and control spin waves in both nanoscale magnetic metals and insulators with low damping by the spin current due to spin Hall e...Spin Hall nano oscillator(SHNO),a new type spintronic nano-device,can electrically excite and control spin waves in both nanoscale magnetic metals and insulators with low damping by the spin current due to spin Hall effect and interfacial Rashba effect.Several spin-wave modes have been excited successfully and investigated substantially in SHNOs based on dozens of different ferromagnetic/nonmagnetic(FM/NM)bilayer systems(e.g.,FM=Py,[Co/Ni],Fe,CoFeB,Y3Fe5O12;NM=Pt,Ta,W).Here,we will review recent progress about spin-wave excitation and experimental parameters dependent dynamics in SHNOs.The nanogap SHNOs with in-plane magnetization exhibit a nonlinear self-localized bullet soliton localized at the center of the gap between the electrodes and a secondary high-frequency mode which coexists with the primary bullet mode at higher currents.While in the nanogap SHNOs with out of plane magnetization,besides both nonlinear bullet soliton and propagating spin-wave mode are achieved and controlled by varying the external magnetic field and current,the magnetic bubble skyrmion mode also can be excited at a low in-plane magnetic field.These spin-wave modes show thermal-induced mode hopping behavior at high temperature due to the coupling between the modes mediated by thermal magnon mediated scattering.Moreover,thanks to the perpendicular magnetic anisotropy induced effective field,the single coherent mode also can be achieved without applying an external magnetic field.The strong nonlinear effect of spin waves makes SHNOs easy to achieve synchronization with external microwave signals or mutual synchronization between multiple oscillators which improve the coherence and power of oscillation modes significantly.Spin waves in SHNOs with an external free magnetic layer have a wide range of applications from as a nanoscale signal source of low power consumption magnonic devices to spin-based neuromorphic computing systems in the field of artificial intelligence.展开更多
Optimization of intrinsic structure of electrode materials plays decisive roles in promoting the development of energy storage systems to meet the fast-growing requirements in the market.Interlayer engineering has bee...Optimization of intrinsic structure of electrode materials plays decisive roles in promoting the development of energy storage systems to meet the fast-growing requirements in the market.Interlayer engineering has been proved to be an effective way to obtain adequate active sites,preferable ion diffusion channels and stable structure,thus enhance the performance of batteries.An in-depth understanding of the correlation among synthesis,structure and performance will significantly promote the development of excellent materials and energy storage devices.Therefore,in this review,recent advances in regards to cation preintercalation engineering in Mn-based electrode materials for rechargeable metal ion batteries are systematically summarized.Preintercalated guest cations can expand interlayer space to promote ion diffusion kinetics,serve as pillars to stabilize structure,control composition and valence to switch electrochemical behavior,thus improve the overall performance of secondary batteries.Moreover,the existing challenges and perspectives are provided for the interlayer engineering and its promotion to battery industry.展开更多
We report the temperature dependence of the spin pumping effect for Y_(3)Fe_(5)O_(12)(YIG,0.9μm)/NiO(tNiO)/W(6 nm)(tNiO=0 nm,1 nm,2 nm,and 10 nm)heterostructures.All samples exhibit a strong temperature-dependent inv...We report the temperature dependence of the spin pumping effect for Y_(3)Fe_(5)O_(12)(YIG,0.9μm)/NiO(tNiO)/W(6 nm)(tNiO=0 nm,1 nm,2 nm,and 10 nm)heterostructures.All samples exhibit a strong temperature-dependent inverse spin Hall effect(ISHE)signal I_(c)and sensitivity to the NiO layer thickness.We observe a dramatic decrease of I_(c)with inserting thin NiO layer between YIG and W layers indicating that the inserting of NiO layer significantly suppresses the spin transport from YIG to W.In contrast to the noticeable enhancement in YIG/NiO(tNiO≈1-2 nm)/Pt,the suppression of spin transport may be closely related to the specific interface-dependent spin scattering,spin memory loss,and spin conductance at the NiO/W interface.Besides,the I_(c)of YIG/Ni O/W exhibits a maximum near the TNof the AF NiO layer because the spins are transported dominantly by incoherent thermal magnons.展开更多
We systematically investigated the Ni and Co thickness-dependent perpendicular magnetic anisotropy(PMA)coefficient,magnetic domain structures,and magnetization dynamics of Pt(5 nm)/[Co(t_(Co))/Ni(t_(Ni))]_(5)/Pt(1 nm)...We systematically investigated the Ni and Co thickness-dependent perpendicular magnetic anisotropy(PMA)coefficient,magnetic domain structures,and magnetization dynamics of Pt(5 nm)/[Co(t_(Co))/Ni(t_(Ni))]_(5)/Pt(1 nm)multilayers by combining the four standard magnetic characterization techniques.The magnetic-related hysteresis loops obtained from the field-dependent magnetization M and anomalous Hall resistivity(AHR)ρxy showed that the two serial multilayers with t_(Co)=0.2 nm and 0.3 nm have the optimum PMA coefficient K_(U) as well as the highest coercivity H_(C) at the Ni thickness t_(Ni)=0.6 nm.Additionally,the magnetic domain structures obtained by magneto-optic Kerr effect(MOKE)microscopy also significantly depend on the thickness and K_(U) of the films.Furthermore,the thickness-dependent linewidth of ferromagnetic resonance is inversely proportional to K_(U) and H_(C),indicating that inhomogeneous magnetic properties dominate the linewidth.However,the intrinsic Gilbert damping constant determined by a linear fitting of the frequency-dependent linewidth does not depend on the Ni thickness and K_(U).Our results could help promote the PMA[Co/Ni]multilayer applications in various spintronic and spin-orbitronic devices.展开更多
We study inserting Co layer thickness-dependent spin transport and spin-orbit torques(SOTs)in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance.The interfacial perpendicular magnetic anisotropy(IPMA)energy...We study inserting Co layer thickness-dependent spin transport and spin-orbit torques(SOTs)in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance.The interfacial perpendicular magnetic anisotropy(IPMA)energy density(Ks=2.7 erg/cm^(2),1 erg=10^(-7) J),which is dominated by interfacial spin-orbit coupling(ISOC)in the Pt/Co interface,total effective spin-mixing conductance(G↑↓eff,tot=0.42×10^(15) Ω^(-1)·m^(-2))and two-magnon scattering(βTMS=0.46 nm2)are first characterized,and the damping-like torque(ξDL=0.103)and field-like torque(ξFL=-0.017)efficiencies are also calculated quantitatively by varying the thickness of the inserting Co layer.The significant enhancement of ξDL and ξFL in Pt/Co/Py than Pt/Py bilayer system originates from the interfacial Rashba-Edelstein effect due to the strong ISOC between Co-3d and Pt-5d orbitals at the Pt/Co interface.Additionally,we find a considerable out-of-plane spin polarization SOT,which is ascribed to the spin anomalous Hall effect and possible spin precession effect due to IPMA-induced perpendicular magnetization at the Pt/Co interface.Our results demonstrate that the ISOC of the Pt/Co interface plays a vital role in spin transport and SOTs-generation.Our finds offer an alternative approach to improve the conventional SOTs efficiencies and generate unconventional SOTs with out-of-plane spin polarization to develop low power Pt-based spintronic via tailoring the Pt/FM interface.展开更多
Artificial spin ice(ASI) structures have significant technological potential as reconfigurable metamaterials and magnetic storage media.We investigate the field/frequency-dependent magnetic dynamics of a kagome ASI ma...Artificial spin ice(ASI) structures have significant technological potential as reconfigurable metamaterials and magnetic storage media.We investigate the field/frequency-dependent magnetic dynamics of a kagome ASI made of 25-nm-thick permalloy nanomagnet elements,combining magnetoresistance(MR) and microscale ferromagnetic resonance(FMR) techniques.Our FMR spectra show a broadband absorption spectrum from 0.2 GHz to 3 GHz at H below 0.3 kOe,where the magnetic configuration of the kagome ASI is in the multidomain state,because the external magnetic field is below the obtained coercive field Hc~0.3 kOe,based on both the low-field range MR loops and simulations,suggesting that the low-field magnetization dynamics of kagome ASI is dominated by a multimode resonance regime.However,the FMR spectra exhibit five distinctive resonance modes at the highfield quasi-uniform magnetization state.Furthermore,our micromagnetic simulations provide additional spatial resolution of these resonance modes,identifying the presence of two high-frequency primary modes,localized in the horizontal and vertical bars of the ASI,respectively;three other low-frequency modes are mutually exclusive and separately pinned at the corners of the kagome ASI by an edge-induced dipolar field.Our results suggest that an ASI structural design can be adopted as an efficient approach for the development of low-power filters and magnonic devices.展开更多
We report a perpendicular magnetic tunnel junction(p MTJ)cell with a tunnel magnetoresistance(TMR)ratio of nearly 200%at room temperature based on Co Fe B/Ta/Co Fe B as the free layer(FL)and a synthetic antiferromagne...We report a perpendicular magnetic tunnel junction(p MTJ)cell with a tunnel magnetoresistance(TMR)ratio of nearly 200%at room temperature based on Co Fe B/Ta/Co Fe B as the free layer(FL)and a synthetic antiferromagnetic(SAF)multilayer[Pt/Co]/Ru/[Pt/Co]/Ta/Co Fe B as the reference layer(RL).The field-driven magnetization switching measurements show that the p MTJs exhibit an anomalous TMR hysteresis loop.The spin-polarized layer Co Fe B of SAF-RL has a lower critical switching field than that of FL.The reason is related to the interlayer exchange coupling(IEC)through a moderately thick Ta spacer layer among SAF-RLs,which generates a moderate and negative bias magnetic field on Co Fe B of RL.However,the IEC among RLs has a negligible influence on the current-driven magnetization switching of FL and its magnetization dynamics.展开更多
Magnonic devices based on spin waves are considered as a new generation of energy-efficient and high-speed devices for storage and processing of information.Here we experimentally demonstrate that three distinct domin...Magnonic devices based on spin waves are considered as a new generation of energy-efficient and high-speed devices for storage and processing of information.Here we experimentally demonstrate that three distinct dominated magneto-dynamic modes are excited simultaneously and coexist in a transversely magnetized ferromagnetic wire by the ferromagnetic resonance(FMR)technique.Besides the uniform FMR mode,the spin-wave well mode,the backward volume magnetostatic spin-wave mode,and the perpendicular standing spin-wave mode are experimentally observed and further confirmed with more detailed spatial profiles by micromagnetic simulation.Furthermore,our experimental approach can also access and reveal damping coefficients of these spin-wave modes,which provides essential information for development of magnonic devices in the future.展开更多
Neuropathic pain is a long term and common pain disorder in clinics that is refractory to treatment,however,the neural substrates and underlying mechanisms are poorly understood.Using the com bination of neuronal mapp...Neuropathic pain is a long term and common pain disorder in clinics that is refractory to treatment,however,the neural substrates and underlying mechanisms are poorly understood.Using the com bination of neuronal mapping,optogenetics,chemogenetics,eletrophysiological recording,in vivo fiber photometry and behavioral testing,we previously identified a new neural circuit of BLA-mPFC-vIPAG and its key role in encoding and modulation of the spared nerve injury(SNI)-induced neuropathic pain..Here we report that the V M-vlOFC-vIPAG circuit modulates neuropathic pain and dissects the underlying mechanisms at cellular and circuitry level.展开更多
基金funded by the National Natural Science Foundation of China(U21B2057,12102328,and 52372252)the Newly Introduced Scientific Research Start-up Funds for Hightech Talents(DD11409024).
文摘Zinc-ion batteries are promising for large-scale electrochemical energy storage systems,which still suffer from interfacial issues,e.g.,hydrogen evolution side reaction(HER),self-corrosion,and uncontrollable dendritic Zn electrodeposition.Although the regulation of electric double layer(EDL)has been verified for interfacial issues,the principle to select the additive as the regulator is still misted.Here,several typical amino acids with different characteristics were examined to reveal the interfacial behaviors in regulated EDL on the Zn anode.Negative charged acidic polarity(NCAP)has been unveiled as the guideline for selecting additive to reconstruct EDL with an inner zincophilic H_(2)O-poor layer and to replace H_(2)O molecules of hydrated Zn^(2+)with NCAP glutamate.Taking the synergistic effects of EDL regulation,the uncontrollable interface is significantly stabilized from the suppressed HER and anti-self-corrosion with uniform electrodeposition.Consequently,by adding NCAP glutamate,a high average Coulombic efficiency of 99.83%of Zn metal is achieved in Zn|Cu asymmetrical cell for over 2000 cycles,and NH4V4O10|Zn full cell exhibits a high-capacity retention of 82.1%after 3000 cycles at 2 A g^(-1).Recapitulating,the NCAP principle posted here can quicken the design of trailblazing electrolyte additives for aqueous Zn-based electrochemical energy storage systems.
基金financially supported by the Fundamental Research Funds of Shangdong University(2016JC005,2017JC042,2017JC010)High-level Talents’Discipline Construction Fund of Shandong University(31370089963078)+1 种基金Technology Major Project(2017CXGC1010,2018JMRH0211,ZR2017MEM002)School research startup expenses of Harbin Institute of Technology(Shenzhen)(DD29100027)。
文摘For the applications of aqueous Li-ion hybrid capacitors and Na-ion hybrid capacitors,potassium ions are pre-inserted into MnO2 tunnel structure,the as-prepared K1.04Mn8 O16 materials consist of nanoparticles and nanorods were prepared by facile high-temperature solid-state reaction.The as-prepared materials were well studied and they show outstanding electrochemical behavior.We assembled hybrid supercapacitors with commercial activated carbon(YEC-8 A)as anode and K1.04Mn8 O16 as cathode.It shows high energy and power densities.Li-ion capacitors reach a high energy density of 127.61 Wh kg-1 at the power density of 99.86 W kg-1 and Na-ion capacitor obtains 170.96 Wh kg-1 at 133.79 W kg-1.In addition,the hybrid supercapacitors demonstrate excellent cycling performance which maintain 97%capacitance retention for Li-ion capacitor and 85%for Na-ion capacitor after 10,000 cycles.
基金Project supported by State Grid Corporation of China under the 2018 Science and Technology Project of State Grid Corporation:Research on electromagnetic measurement technology based on EIT and TMR(Grant No.JL71-18-007)。
文摘We investigate properties of perpendicular anisotropy magnetic tunnel junctions(pMTJs) with a stack structure MgO/CoFeB/Ta/CoFeB/MgO as the free layer(or recording layer),and obtain the necessary device parameters from the tunneling magnetoresistance(TMR) vs.field loops and current-driven magnetization switching experiments.Based on the experimental results and device parameters,we further estimate current-driven switching performance of pMTJ including switching time and power,and their dependence on perpendicular magnetic anisotropy and damping constant of the free layer by SPICE-based circuit simulations.Our results show that the pMTJ cells exhibit a less than 1 ns switching time and write energies <1.4 pJ;meanwhile the lower perpendicular magnetic anisotropy(PMA) and damping constant can further reduce the switching time at the studied range of damping constant α <0.1.Additionally,our results demonstrate that the pMTJs with the thermal stability factor■73 can be easily transformed into spin-torque nano-oscillators from magnetic memory as microwave sources or detectors for telecommunication devices.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0300803)the National Natural Science Foundation of China(Grant Nos.11774150,12074178,and 12004171)+1 种基金the Applied Basic Research Programs of Science and Technology Commission Foundation of Jiangsu Province,China(Grant No.BK20170627)the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnology.
文摘Spin Hall nano oscillator(SHNO),a new type spintronic nano-device,can electrically excite and control spin waves in both nanoscale magnetic metals and insulators with low damping by the spin current due to spin Hall effect and interfacial Rashba effect.Several spin-wave modes have been excited successfully and investigated substantially in SHNOs based on dozens of different ferromagnetic/nonmagnetic(FM/NM)bilayer systems(e.g.,FM=Py,[Co/Ni],Fe,CoFeB,Y3Fe5O12;NM=Pt,Ta,W).Here,we will review recent progress about spin-wave excitation and experimental parameters dependent dynamics in SHNOs.The nanogap SHNOs with in-plane magnetization exhibit a nonlinear self-localized bullet soliton localized at the center of the gap between the electrodes and a secondary high-frequency mode which coexists with the primary bullet mode at higher currents.While in the nanogap SHNOs with out of plane magnetization,besides both nonlinear bullet soliton and propagating spin-wave mode are achieved and controlled by varying the external magnetic field and current,the magnetic bubble skyrmion mode also can be excited at a low in-plane magnetic field.These spin-wave modes show thermal-induced mode hopping behavior at high temperature due to the coupling between the modes mediated by thermal magnon mediated scattering.Moreover,thanks to the perpendicular magnetic anisotropy induced effective field,the single coherent mode also can be achieved without applying an external magnetic field.The strong nonlinear effect of spin waves makes SHNOs easy to achieve synchronization with external microwave signals or mutual synchronization between multiple oscillators which improve the coherence and power of oscillation modes significantly.Spin waves in SHNOs with an external free magnetic layer have a wide range of applications from as a nanoscale signal source of low power consumption magnonic devices to spin-based neuromorphic computing systems in the field of artificial intelligence.
基金financially supported by the School Research Startup Expenses of Harbin Institute of Technology(Shenzhen)(DD29100027)the High-level Talents’Discipline Construction Fund of Shandong University(No.31370089963078)+2 种基金the Shandong Provincial Science and Technology Major Project(Nos.2016GGX10^(4)001,2017CXGC1010,and 2018JMRH0211)the Fundamental Research Funds of Shandong University(Nos.2016JC005,2017JC042 and 2017JC010)the Natural Science Foundation of Shandong Province(No.ZR2017MEM002)。
文摘Optimization of intrinsic structure of electrode materials plays decisive roles in promoting the development of energy storage systems to meet the fast-growing requirements in the market.Interlayer engineering has been proved to be an effective way to obtain adequate active sites,preferable ion diffusion channels and stable structure,thus enhance the performance of batteries.An in-depth understanding of the correlation among synthesis,structure and performance will significantly promote the development of excellent materials and energy storage devices.Therefore,in this review,recent advances in regards to cation preintercalation engineering in Mn-based electrode materials for rechargeable metal ion batteries are systematically summarized.Preintercalated guest cations can expand interlayer space to promote ion diffusion kinetics,serve as pillars to stabilize structure,control composition and valence to switch electrochemical behavior,thus improve the overall performance of secondary batteries.Moreover,the existing challenges and perspectives are provided for the interlayer engineering and its promotion to battery industry.
基金support from the National Natural Science Foundation of China(Grant Nos.11774160,61427812,61805116,12004171,61774081,and 62171096)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20192006)+4 种基金the National Key Scientific Instrument and Equipment Development Project of China(Grant No.51827802)the Natural Science Foundation of Jiangsu Province of China(Grant Nos.BK20180056 and BK20200307)the Applied Basic Research Programs of the Science and Technology Commission Foundation of Jiangsu Province,China(Grant No.BK20200309)the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnology,the Scientific Foundation of Nanjing University of Posts and Telecommunications(NUPTSF)(Grant No.NY220164)the State Key R&D Project of Guangdong,China(Grant No.2020B010174002)
文摘We report the temperature dependence of the spin pumping effect for Y_(3)Fe_(5)O_(12)(YIG,0.9μm)/NiO(tNiO)/W(6 nm)(tNiO=0 nm,1 nm,2 nm,and 10 nm)heterostructures.All samples exhibit a strong temperature-dependent inverse spin Hall effect(ISHE)signal I_(c)and sensitivity to the NiO layer thickness.We observe a dramatic decrease of I_(c)with inserting thin NiO layer between YIG and W layers indicating that the inserting of NiO layer significantly suppresses the spin transport from YIG to W.In contrast to the noticeable enhancement in YIG/NiO(tNiO≈1-2 nm)/Pt,the suppression of spin transport may be closely related to the specific interface-dependent spin scattering,spin memory loss,and spin conductance at the NiO/W interface.Besides,the I_(c)of YIG/Ni O/W exhibits a maximum near the TNof the AF NiO layer because the spins are transported dominantly by incoherent thermal magnons.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11774150,12074178,12004171,12074189,and 51971109)the Applied Basic Research Programs of Science and Technology Commission Foundation of Jiangsu Province,China (Grant No.BK20170627)+2 种基金the National Key Research and Development Program of China (Grant No.2018YFA0209002)the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnologythe Scientific Foundation of Nanjing University of Posts and Telecommunications (NUPTSF) (Grant No.NY220164)。
文摘We systematically investigated the Ni and Co thickness-dependent perpendicular magnetic anisotropy(PMA)coefficient,magnetic domain structures,and magnetization dynamics of Pt(5 nm)/[Co(t_(Co))/Ni(t_(Ni))]_(5)/Pt(1 nm)multilayers by combining the four standard magnetic characterization techniques.The magnetic-related hysteresis loops obtained from the field-dependent magnetization M and anomalous Hall resistivity(AHR)ρxy showed that the two serial multilayers with t_(Co)=0.2 nm and 0.3 nm have the optimum PMA coefficient K_(U) as well as the highest coercivity H_(C) at the Ni thickness t_(Ni)=0.6 nm.Additionally,the magnetic domain structures obtained by magneto-optic Kerr effect(MOKE)microscopy also significantly depend on the thickness and K_(U) of the films.Furthermore,the thickness-dependent linewidth of ferromagnetic resonance is inversely proportional to K_(U) and H_(C),indicating that inhomogeneous magnetic properties dominate the linewidth.However,the intrinsic Gilbert damping constant determined by a linear fitting of the frequency-dependent linewidth does not depend on the Ni thickness and K_(U).Our results could help promote the PMA[Co/Ni]multilayer applications in various spintronic and spin-orbitronic devices.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774150,12074178,11874135,and 12004171)the Applied Basic Research Programs of the Science and Technology Commission Foundation of Jiangsu Province,China(Grant No.BK20200309)+1 种基金the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnology,Key Research and Development Program of Zhejiang Province,China(Grant No.2021C01039)the Scientific Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY220164).
文摘We study inserting Co layer thickness-dependent spin transport and spin-orbit torques(SOTs)in the Pt/Co/Py trilayers by spin-torque ferromagnetic resonance.The interfacial perpendicular magnetic anisotropy(IPMA)energy density(Ks=2.7 erg/cm^(2),1 erg=10^(-7) J),which is dominated by interfacial spin-orbit coupling(ISOC)in the Pt/Co interface,total effective spin-mixing conductance(G↑↓eff,tot=0.42×10^(15) Ω^(-1)·m^(-2))and two-magnon scattering(βTMS=0.46 nm2)are first characterized,and the damping-like torque(ξDL=0.103)and field-like torque(ξFL=-0.017)efficiencies are also calculated quantitatively by varying the thickness of the inserting Co layer.The significant enhancement of ξDL and ξFL in Pt/Co/Py than Pt/Py bilayer system originates from the interfacial Rashba-Edelstein effect due to the strong ISOC between Co-3d and Pt-5d orbitals at the Pt/Co interface.Additionally,we find a considerable out-of-plane spin polarization SOT,which is ascribed to the spin anomalous Hall effect and possible spin precession effect due to IPMA-induced perpendicular magnetization at the Pt/Co interface.Our results demonstrate that the ISOC of the Pt/Co interface plays a vital role in spin transport and SOTs-generation.Our finds offer an alternative approach to improve the conventional SOTs efficiencies and generate unconventional SOTs with out-of-plane spin polarization to develop low power Pt-based spintronic via tailoring the Pt/FM interface.
基金the State Grid Corporation of China via the Science and Technology Project:Research on Electromagnetic Measurement Technology Based on EIT and TMR(Grant No.JL71-18-007)。
文摘Artificial spin ice(ASI) structures have significant technological potential as reconfigurable metamaterials and magnetic storage media.We investigate the field/frequency-dependent magnetic dynamics of a kagome ASI made of 25-nm-thick permalloy nanomagnet elements,combining magnetoresistance(MR) and microscale ferromagnetic resonance(FMR) techniques.Our FMR spectra show a broadband absorption spectrum from 0.2 GHz to 3 GHz at H below 0.3 kOe,where the magnetic configuration of the kagome ASI is in the multidomain state,because the external magnetic field is below the obtained coercive field Hc~0.3 kOe,based on both the low-field range MR loops and simulations,suggesting that the low-field magnetization dynamics of kagome ASI is dominated by a multimode resonance regime.However,the FMR spectra exhibit five distinctive resonance modes at the highfield quasi-uniform magnetization state.Furthermore,our micromagnetic simulations provide additional spatial resolution of these resonance modes,identifying the presence of two high-frequency primary modes,localized in the horizontal and vertical bars of the ASI,respectively;three other low-frequency modes are mutually exclusive and separately pinned at the corners of the kagome ASI by an edge-induced dipolar field.Our results suggest that an ASI structural design can be adopted as an efficient approach for the development of low-power filters and magnonic devices.
基金Supported by the National Key Research and Development Program of China(Grant No.2016YFA0300803)the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnology+1 种基金the National Natural Science Foundation of China(Grant Nos.11774150 and 11874135)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20170627)。
文摘We report a perpendicular magnetic tunnel junction(p MTJ)cell with a tunnel magnetoresistance(TMR)ratio of nearly 200%at room temperature based on Co Fe B/Ta/Co Fe B as the free layer(FL)and a synthetic antiferromagnetic(SAF)multilayer[Pt/Co]/Ru/[Pt/Co]/Ta/Co Fe B as the reference layer(RL).The field-driven magnetization switching measurements show that the p MTJs exhibit an anomalous TMR hysteresis loop.The spin-polarized layer Co Fe B of SAF-RL has a lower critical switching field than that of FL.The reason is related to the interlayer exchange coupling(IEC)through a moderately thick Ta spacer layer among SAF-RLs,which generates a moderate and negative bias magnetic field on Co Fe B of RL.However,the IEC among RLs has a negligible influence on the current-driven magnetization switching of FL and its magnetization dynamics.
基金Supported by the National Key Research and Development Program of China(Grant No.2016YFA0300803)the Open Research Fund of Jiangsu Provincial Key Laboratory for Nanotechnology,the National Natural Science Foundation of China(Grant Nos.11774150 and 11704191)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20171026 and BK20170627).
文摘Magnonic devices based on spin waves are considered as a new generation of energy-efficient and high-speed devices for storage and processing of information.Here we experimentally demonstrate that three distinct dominated magneto-dynamic modes are excited simultaneously and coexist in a transversely magnetized ferromagnetic wire by the ferromagnetic resonance(FMR)technique.Besides the uniform FMR mode,the spin-wave well mode,the backward volume magnetostatic spin-wave mode,and the perpendicular standing spin-wave mode are experimentally observed and further confirmed with more detailed spatial profiles by micromagnetic simulation.Furthermore,our experimental approach can also access and reveal damping coefficients of these spin-wave modes,which provides essential information for development of magnonic devices in the future.
文摘Neuropathic pain is a long term and common pain disorder in clinics that is refractory to treatment,however,the neural substrates and underlying mechanisms are poorly understood.Using the com bination of neuronal mapping,optogenetics,chemogenetics,eletrophysiological recording,in vivo fiber photometry and behavioral testing,we previously identified a new neural circuit of BLA-mPFC-vIPAG and its key role in encoding and modulation of the spared nerve injury(SNI)-induced neuropathic pain..Here we report that the V M-vlOFC-vIPAG circuit modulates neuropathic pain and dissects the underlying mechanisms at cellular and circuitry level.
