Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SO...Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SOC)has limited its efficiency for generating the spin currents in order to control the magnetization switching process for applications in spintronics memories.Following the theoretical prediction on the enhancement of SOC in Gr by heavy atoms adsorption,here we experimentally observe a sizeable spin–orbit torques(SOTs)in Gr by the decoration of its surface with Pt adatoms in Gr/Pt(t Pt)/Fe Ni trilayers with the optimal damping-like SOT efficiency around 0.55 by 0.6-nm-thick Pt layer adsorption.The value is nearly four times larger than that of the Pt/Fe Ni sample without Gr and nearly twice the value of the Gr/Fe Ni sample without Pt adsorption.The efficiency of the enhanced SOT in Gr by Pt adatoms is also demonstrated by the field-free SOT magnetization switching process with a relatively low critical current density around 5.4 MA/cm^(2)in Gr/Pt/Fe Ni trilayers with the in-plane magnetic anisotropy.These findings pave the way for Gr spintronics applications,offering solutions for future low power consumption memories.展开更多
The spin–orbit torque via the spin Hall effect of heavy metals has shown promising prospect in driving the magnetization switching in spintronic devices due to the generated spin current from heavy metals.Recently,th...The spin–orbit torque via the spin Hall effect of heavy metals has shown promising prospect in driving the magnetization switching in spintronic devices due to the generated spin current from heavy metals.Recently,the 3d-light metals have been predicted the ability to generate orbital current and the associated orbital torques from the orbital Hall effect.However,few experiments have been carried out since it is quite hard to directly detect the orbital current-generated orbital torque.Here,we report an effective method to demonstrate the strong orbital torques in light metal Cr through a conversion process from orbital current to spin current by introducing the Pt interfacial layer in perpendicularly magnetized symmetric Pt/Co/Pt structures.A quite large and monotonically growth of orbital torque efficiency in Pt/Co/Pt/Cr with the increase of the thickness of Cr layer is obtained with the largest effective orbital torque efficiency around 2.6 Oe/(MA·cm^(-2))(1 Oe=79.5775 A·m^(-1)).The ability of orbital torque to drive the magnetization switching is also reported with the critical switching current density down to the order of 106A·cm^(-2).Our findings prove the efficiency for switching the magnetization from light metal Cr layers through the orbital Hall effect.展开更多
The effect of the volume fraction of ferromagnetic metal （x） in （Ni75Fe25）x（ZnO）1-x nanogranular thin films on microstructural, soft-magnetic, and high-frequency properties was investigated. Good soft-magnetic p...The effect of the volume fraction of ferromagnetic metal （x） in （Ni75Fe25）x（ZnO）1-x nanogranular thin films on microstructural, soft-magnetic, and high-frequency properties was investigated. Good soft-magnetic properties were obtained in a broad x range, with 0.55 〈 x 〈 0.82. High resolution transmission electron microscopy （HRTEM） observations reveal that the grain size of the samples is lower than 14 nm, and that it decreases with decreasing x. Of special interest, our investigation of the permeability spectra indicates that these films exhibit an adjustable frequency linewidth of resonance peak, dependant upon changing x. Correspondingly, large and adjustable damping coefficients （aeff） from 0.023 to 0.043 were achieved by decreasing x from 0.82 to 0.55. Combined with the HRTEM results, the variation of αeff with x was analyzed in detail.展开更多
This paper obtains the room temperature ferromagnetism in Sn1-x FexO2 films fabricated by the Sol-Gel method. X-ray diffraction results show that Fe doping inhibits the growth of SnO2 and Fe^3＋ ions occupy the Sn sit...This paper obtains the room temperature ferromagnetism in Sn1-x FexO2 films fabricated by the Sol-Gel method. X-ray diffraction results show that Fe doping inhibits the growth of SnO2 and Fe^3＋ ions occupy the Sn sites. The measurement of resistance excludes the free carrier inducing ferromagnetism. Moreover, the temperature dependence of magnetization has been better fitted by the Curie Weiss law and bound magnetic polaron （BMP） theory. An enhancement of ferromagnetism is achieved by annealing the samples with x = 7.1% in H2, and a decrease of oxygen flow rate. All these results prove that the BMP model depending on defects can explain ferromagnetism in diluted magnetic oxides.展开更多
基金supported by the National Key R&D Program of China(Grant No.2021YFB3501304)the National Natural Science Foundation of China(Grant Nos.91963201 and 51671098)+4 种基金the 111 Project(Grant No.B20063)the Open Research Fund of Songshan Lake Materials Laboratory(Grant No.2023SLABFN05)the Program for Changjiang Scholars and Innovative Research Team in University PCSIRT(Grant No.IRT16R35)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021-ct01)the Natural Science Foundation of Gansu Province(Grant No.22JR5RA474)。
文摘Graphene(Gr)with widely acclaimed characteristics,such as exceptionally long spin diffusion length at room temperature,provides an outstanding platform for spintronics.However,its inherent weak spin–orbit coupling(SOC)has limited its efficiency for generating the spin currents in order to control the magnetization switching process for applications in spintronics memories.Following the theoretical prediction on the enhancement of SOC in Gr by heavy atoms adsorption,here we experimentally observe a sizeable spin–orbit torques(SOTs)in Gr by the decoration of its surface with Pt adatoms in Gr/Pt(t Pt)/Fe Ni trilayers with the optimal damping-like SOT efficiency around 0.55 by 0.6-nm-thick Pt layer adsorption.The value is nearly four times larger than that of the Pt/Fe Ni sample without Gr and nearly twice the value of the Gr/Fe Ni sample without Pt adsorption.The efficiency of the enhanced SOT in Gr by Pt adatoms is also demonstrated by the field-free SOT magnetization switching process with a relatively low critical current density around 5.4 MA/cm^(2)in Gr/Pt/Fe Ni trilayers with the in-plane magnetic anisotropy.These findings pave the way for Gr spintronics applications,offering solutions for future low power consumption memories.
基金the National Natural Science Foundation of China(Grant Nos.91963201 and 51671098)the 111 Project(Grant No.B20063)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University PCSIRT(Grant No.IRT16R35)the Natural Science Foundation of Gansu Province,China(Grant No.22JR5RA474).
文摘The spin–orbit torque via the spin Hall effect of heavy metals has shown promising prospect in driving the magnetization switching in spintronic devices due to the generated spin current from heavy metals.Recently,the 3d-light metals have been predicted the ability to generate orbital current and the associated orbital torques from the orbital Hall effect.However,few experiments have been carried out since it is quite hard to directly detect the orbital current-generated orbital torque.Here,we report an effective method to demonstrate the strong orbital torques in light metal Cr through a conversion process from orbital current to spin current by introducing the Pt interfacial layer in perpendicularly magnetized symmetric Pt/Co/Pt structures.A quite large and monotonically growth of orbital torque efficiency in Pt/Co/Pt/Cr with the increase of the thickness of Cr layer is obtained with the largest effective orbital torque efficiency around 2.6 Oe/(MA·cm^(-2))(1 Oe=79.5775 A·m^(-1)).The ability of orbital torque to drive the magnetization switching is also reported with the critical switching current density down to the order of 106A·cm^(-2).Our findings prove the efficiency for switching the magnetization from light metal Cr layers through the orbital Hall effect.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50901050 and 51101079)
文摘The effect of the volume fraction of ferromagnetic metal （x） in （Ni75Fe25）x（ZnO）1-x nanogranular thin films on microstructural, soft-magnetic, and high-frequency properties was investigated. Good soft-magnetic properties were obtained in a broad x range, with 0.55 〈 x 〈 0.82. High resolution transmission electron microscopy （HRTEM） observations reveal that the grain size of the samples is lower than 14 nm, and that it decreases with decreasing x. Of special interest, our investigation of the permeability spectra indicates that these films exhibit an adjustable frequency linewidth of resonance peak, dependant upon changing x. Correspondingly, large and adjustable damping coefficients （aeff） from 0.023 to 0.043 were achieved by decreasing x from 0.82 to 0.55. Combined with the HRTEM results, the variation of αeff with x was analyzed in detail.
文摘This paper obtains the room temperature ferromagnetism in Sn1-x FexO2 films fabricated by the Sol-Gel method. X-ray diffraction results show that Fe doping inhibits the growth of SnO2 and Fe^3＋ ions occupy the Sn sites. The measurement of resistance excludes the free carrier inducing ferromagnetism. Moreover, the temperature dependence of magnetization has been better fitted by the Curie Weiss law and bound magnetic polaron （BMP） theory. An enhancement of ferromagnetism is achieved by annealing the samples with x = 7.1% in H2, and a decrease of oxygen flow rate. All these results prove that the BMP model depending on defects can explain ferromagnetism in diluted magnetic oxides.
