Adjustable Current‐Induced Magnetization Switching Utilizing Interlayer Exchange Coupling

Sheng, Yu; Edmonds, K. W.; Ma, Xingqiao; Zheng, Hang; Wang, Kaiyou

doi:10.1002/aelm.201800224

Cited by 115 publications

(68 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To realize this aim, we design the device in heavy metal (HM)/FM/AFM/FM structure, where the bottom and top FM layers are perpendicular magnetic anisotropy (PMA) and in-plane anisotropy, respectively. 29 In this work, we report the tunability of VMS and EB by SOT in at positive (2200 Oe) and negative (-2200 Oe) field, respectively], which is much larger than that reported in conventional field-cooling AFM/FM system. [9][10][11][12] As the positive and negative Ip have nearly the same effect on switching out-of-plane interfacial spins under Hz, 28 we measured the device using a single pulse 40 mA under Hz = -2 kOe [ Fig.…”

mentioning

confidence: 70%

Controlling vertical magnetization shift by spin–orbit torque in ferromagnetic/antiferromagnetic/ferromagnetic heterostructure

Zhou

Liu

Wang

2020

Applied Physics Letters

View full text Add to dashboard Cite

We report the control of vertical magnetization shift (VMS) and exchange bias through spin-orbit torque (SOT) in Pt/Co/Ir25Mn75/Co heterostructure device. The exchange bias accompanying with a large relative VMS of about 30 % is observed after applying a single pulse 40 mA in perpendicular field of 2 kOe. Furthermore, the field-free SOT-induced variations of VMS and exchange bias is also observed, which would be related to the effective built-in out-of-plane field due to unequal upward and downward interfacial spin populations. The SOT-induced switched fraction of out-of-plane interfacial spins shows a linear dependence on relative VMS, indicating the number of uncompensated pinned spins are proportional to the switched interfacial spins. Our finding offers a comprehensive understanding for electrically manipulating interfacial spins of AFM materials.Exchange bias (EB) refers to a shift in the hysteresis loop along the magnetic

show abstract

mentioning

confidence: 70%

Controlling vertical magnetization shift by spin–orbit torque in ferromagnetic/antiferromagnetic/ferromagnetic heterostructure

Zhou

Liu

Wang

2020

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…[20] The interlayer exchange coupling due to Ruderman-Kittel-Kasuya-Yosida interaction between two FM layers has been also used to enable field-free magnetization switching. [18] In this study, the symmetry of two states of perpendicular magnetization was broken due to the exchange coupling to a layer with in-plane magnetization. Thus, the deterministic switching could be achieved and, moreover, could be tuned by switching the in-plane magnetization direction.…”

Section: Field-free Deterministic Magnetization Switching By Sotsmentioning

confidence: 93%

“…In this study, the symmetry of two states of perpendicular magnetization was broken due to the exchange coupling to a layer with in‐plane magnetization. Thus, the deterministic switching could be achieved and, moreover, could be tuned by switching the in‐plane magnetization direction …”

Section: Manipulation Of Magnetic Materials By Spin–orbit Torquesmentioning

confidence: 99%

“…Thus, the deterministic switching could be achieved and, moreover, could be tuned by switching the in-plane magnetization direction. [18] Cai et al [17] reported that the polarization of PMN-PT ferroelectric substrates can be used to control the spin-orbit torque in the absence of an external magnetic field in a PMN-PT/Pt/CoNiCo/Pt system, as shown in Figure 5a. Before the substrate is polarized, the magnetization deterministically switches to a fixed z direction regardless of whether the current is applied along the x or −x direction.…”

Section: Field-free Deterministic Magnetization Switching By Sotsmentioning

confidence: 99%

See 1 more Smart Citation

Manipulation of Magnetization by Spin–Orbit Torque

Edmonds

Liu

et al. 2018

Adv Quantum Tech

Self Cite

View full text Add to dashboard Cite

The control of magnetization by electric current is a rapidly developing area motivated by a strong synergy between breakthrough basic research discoveries and industrial applications in the fields of magnetic recording, magnetic field sensors, spintronics, and nonvolatile memories. In recent years, the discovery of spin–orbit torque has opened a spectrum of opportunities to manipulate the magnetization efficiently. This article presents a review of the historical background and recent literature focusing on spin–orbit torques (SOTs), highlighting the most exciting new scientific results and suggesting promising future research directions. It starts with an introduction and overview of the underlying physics of spin–orbit coupling effects in bulk and at interfaces, and then describes the use of SOTs to control ferromagnets and antiferromagnets. Finally, the prospects for the future development of spintronic devices based on SOTs are summarized.

show abstract

“…[1][2][3][4][5][6] In the conventional SOT structure of a heavy metal (HM)/ferromagnet (FM) bilayer, in which spin current is generated by spin Hall effect (SHE) in HM and/or interfacial spin-orbit coupling (ISOC) effect at the HM/FM interface, the direction of spin polarization is found to be orthogonal to both charge and spin current directions. [1,3,[10][11][12][13] Among the extensive reports to achieve SOTinduced switching without an external magnetic field, [14][15][16][17][18][19][20] our previous study showed that an out of plane (or z-) component of spin polarization is generated in a magnetic trilayer of FM/ Ti/CoFeB structure, [21] where the bottom FM (top CoFeB) has www.advelectronicmat.de using perpendicular (B z ) or in-plane (B x , B y ) magnetic fields to measure hysteresis loops of the samples. Since the spin polarization is aligned in the film plane, an external magnetic field is required for SOT-induced switching of perpendicular magnetization.…”

Section: Introductionmentioning

confidence: 99%

Material and Thickness Investigation in Ferromagnet/Ta/CoFeB Trilayers for Enhancement of Spin–Orbit Torque and Field‐Free Switching

Ryu

Kang

et al. 2019

Adv Elect Materials

View full text Add to dashboard Cite

in-plane (perpendicular) magnetic anisotropy. The spin current generated from the FM/Ti interface has a spin polarization along the m × y direction, where m is the magnetization direction of the bottom FM. For an FM with m aligned in the x-direction, a spin current with zspin polarization is generated. [22,23] This enables field-free SOT switching of the perpendicular magnetization of the top CoFeB layer.In this work, we investigate the SOTs in FM/Ta/CoFeB trilayers, in which the spin current generated by SHE in Ta can be combined with the interface-generated spin currents. Using various Ta thickness, we perform measurements of SOTinduced effective fields and of magnetization switching with various Ta thicknesses. We observe two interesting points for a sample with a thin Ta layer; first, the sign of the SOT is determined by the bottom FM layer, and is positive for NiFe and negative for CoFeB. Second, SOT-induced switching is achieved without an in-plane magnetic field. These results demonstrate that the interface-generated spin current of the FM/Ta bilayer governs the SOT of a sample with a thin Ta layer. On the other hand, as Ta thickness increases, the sign of the SOT becomes negative irrespective of the bottom FM and which is determined by the Ta, which has a negative spin Hall angle. This demonstrates that the SOT in the trilayer structure is composed of two contributions: SHE in HM and interface-generated spin current of the FM/HM bilayer, suggesting that the proper selection of an FM/HM combination and of the material thickness can enhance the SOT efficiency and induce field-free SOT switching. Results and Discussion Spin-Orbit Torques in FM/Ta/CoFeB TrilayersIn order to investigate SOT in FM/Ta/CoFeB trilayer structures, we employ Ta (5 nm)/FM (4 nm)/Ta (t Ta )/CoFeB (1.0 nm)/ MgO (3.2 nm) structures, where Ta thickness (t Ta ) ranges from 1.0 to 6.0 nm (Figure 1a). The bottom FM is in-plane magnetized CoFeB or NiFe. As the samples share identical material structures, except for the bottom FM, we refer to the trilayer CoFeB or NiFe samples according to the bottom FM layers. We first check the magnetic anisotropy of each layer by Spin-orbit torques (SOTs) in ferromagnet (FM)/Ta/CoFeB trilayers are investigated as a function of Ta thickness. When the Ta is thinner than 1.5 nm, the sign of the SOT exerting on the top perpendicularly magnetized CoFeB depends on the bottom FM layer; it is positive for NiFe and negative for CoFeB. As the Ta thickness increases, the sign becomes negative irrespective of the bottom FM, indicating that SOTs are dominated by Ta, which has a negative spin Hall angle. SOT-induced switching without an in-plane magnetic field is observed in the thickness ranges where the bottom FM or FM/Ta interface-generated SOT is dominant. The results herein demonstrate that proper design of an FM/heavy metal combination and the material thickness can lead to an enhancement of the SOT efficiency and allow for field-free SOT switching.

show abstract

Adjustable Current‐Induced Magnetization Switching Utilizing Interlayer Exchange Coupling

Cited by 115 publications

References 27 publications

Controlling vertical magnetization shift by spin–orbit torque in ferromagnetic/antiferromagnetic/ferromagnetic heterostructure

Controlling vertical magnetization shift by spin–orbit torque in ferromagnetic/antiferromagnetic/ferromagnetic heterostructure

Manipulation of Magnetization by Spin–Orbit Torque

Material and Thickness Investigation in Ferromagnet/Ta/CoFeB Trilayers for Enhancement of Spin–Orbit Torque and Field‐Free Switching

Contact Info

Product

Resources

About