Magneto-ionics,an emerging approach to manipulate magnetism that relies on voltage-driven ion motion,holds the promise to boost energy efficiency in information technologies such as spintronic devices or future non-vo...Magneto-ionics,an emerging approach to manipulate magnetism that relies on voltage-driven ion motion,holds the promise to boost energy efficiency in information technologies such as spintronic devices or future non-von Neumann computing architectures.For this purpose,stability,reversibility,endurance,and ion motion rates need to be synergistically optimized.Among various ions,nitrogen has demonstrated superior magneto-ionic performance compared to classical species such as oxygen or lithium.Here,we show that ternary Co_(1−x)Fe_(x)N compound exhibits an unprecedented nitrogen magneto-ionic response.Partial substitution of Co by Fe in binary CoN is shown to be favorable in terms of generated magnetization,cyclability and ion motion rates.Specifically,the Co_(0.3)5Fe_(0.65)N films exhibit an induced saturation magnetization of 1,500 emu/cm^(3),a magneto-ionic rate of 35.5 emu/(cm^(3)·s)and endurance exceeding 10^(3) cycles.These values significantly surpass those of other existing nitride and oxide systems.This improvement can be attributed to the larger saturation magnetization of Co_(0.35)Fe_(0.65) compared to individual Co and Fe,the nature and size of structural defects in as-grown films of different composition,and the dissimilar formation energies of Fe and Co with N in the various developed crystallographic structures.展开更多
Room temperature electric field controlled magnetism is extremely promising for the next-generation high-performance spintronic devices.Here,based on the ferroelectric switching driven oxygen ion migration in the Ta/C...Room temperature electric field controlled magnetism is extremely promising for the next-generation high-performance spintronic devices.Here,based on the ferroelectric switching driven oxygen ion migration in the Ta/Co/BiFeO_(3)/SrRuO_(3) heterostructures,the magnetic moment,magnetic coercive field,exchange bias field,and junction resistance are reversibly manipulated by tuning the ferroelectric polarization of the BiFeO_(3) layer.All these phenomena are consistently explained by the oxygen ion migration induced CoOx/Co redox effect,which is evidenced by the synchrotron X-ray absorption spectroscopy measurements.Interestingly,owing to the controllable ferroelectric switching dynamics of the BiFeO_(3) thin film,the magnetic coercive field of the Co thin film can be continuously and precisely tuned by controlling the ferroelectric polarization of the BiFeO_(3) thin film,and the manipulating speed of the voltage control of magnetism can be fast to 100 ns.This nonvolatile,stable,reversible,fast,and reproducible voltage control of magnetism shows great potential for designing low-power and high-speed spintronics.展开更多
基金Financial support by the European Union's Horizon 2020 Research and Innovation Programme(BeMAGIC European Training Network,ETN/ITN Marie Skłodowska-Curie grant Nº861145)the European Research Council(2021-ERC-Advanced REMINDS Grant Nº101054687)+2 种基金the Spanish Government(PID2020-116844RBeC21,TED2021-130453B-C22 and PDC2021-121276-C31)the Generalitat de Catalunya(2021-SGR-00651)the MCIN/AEI/10.13039/501100011033&“European Union NextGenerationEU/PRTR”(grant CNS2022-135230)is acknowledged.
文摘Magneto-ionics,an emerging approach to manipulate magnetism that relies on voltage-driven ion motion,holds the promise to boost energy efficiency in information technologies such as spintronic devices or future non-von Neumann computing architectures.For this purpose,stability,reversibility,endurance,and ion motion rates need to be synergistically optimized.Among various ions,nitrogen has demonstrated superior magneto-ionic performance compared to classical species such as oxygen or lithium.Here,we show that ternary Co_(1−x)Fe_(x)N compound exhibits an unprecedented nitrogen magneto-ionic response.Partial substitution of Co by Fe in binary CoN is shown to be favorable in terms of generated magnetization,cyclability and ion motion rates.Specifically,the Co_(0.3)5Fe_(0.65)N films exhibit an induced saturation magnetization of 1,500 emu/cm^(3),a magneto-ionic rate of 35.5 emu/(cm^(3)·s)and endurance exceeding 10^(3) cycles.These values significantly surpass those of other existing nitride and oxide systems.This improvement can be attributed to the larger saturation magnetization of Co_(0.35)Fe_(0.65) compared to individual Co and Fe,the nature and size of structural defects in as-grown films of different composition,and the dissimilar formation energies of Fe and Co with N in the various developed crystallographic structures.
基金supported by the National Key Research and Development Program of China(2019YFA0307900)National Natural Science Foundation of China(51790491,U21A2066,52125204,and 92163210)+1 种基金the fundamental research funds for the central universities(WK2030000035)this work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication.
文摘Room temperature electric field controlled magnetism is extremely promising for the next-generation high-performance spintronic devices.Here,based on the ferroelectric switching driven oxygen ion migration in the Ta/Co/BiFeO_(3)/SrRuO_(3) heterostructures,the magnetic moment,magnetic coercive field,exchange bias field,and junction resistance are reversibly manipulated by tuning the ferroelectric polarization of the BiFeO_(3) layer.All these phenomena are consistently explained by the oxygen ion migration induced CoOx/Co redox effect,which is evidenced by the synchrotron X-ray absorption spectroscopy measurements.Interestingly,owing to the controllable ferroelectric switching dynamics of the BiFeO_(3) thin film,the magnetic coercive field of the Co thin film can be continuously and precisely tuned by controlling the ferroelectric polarization of the BiFeO_(3) thin film,and the manipulating speed of the voltage control of magnetism can be fast to 100 ns.This nonvolatile,stable,reversible,fast,and reproducible voltage control of magnetism shows great potential for designing low-power and high-speed spintronics.
