Magnetoresistance and spin-transfer torque in magnetic tunnel junctions

Sun, J. Z.; Ralph, Daniel

doi:10.1016/j.jmmm.2007.12.008

Cited by 163 publications

(64 citation statements)

References 96 publications

(141 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In an MFTJ, the carrier concentration and/or chemical bonding strength manipulations at the ferroelectric/ferromagnetic interfaces may give rise to an interfacial magnetoelectric effect, which can change the magnetic anisotropy, coercivity, or even the interfacial magnetic structure by an electric field through switchable ferroelectric polarization. [22][23][24][25] This strong interfacial magnetoelectric coupling in MFTJs provides an alternative energy-efficient route to manipulate spins by an electric field besides the spin transfer torque 26 and electric field assisted switching effects 27 in MTJs. Meanwhile, the interrelationship between ferroelectricity of the barrier layer and ferromagnetism of the electrodes through an interface magnetoelectric effect also affects the functional properties of TMR and TER in MFTJs.…”

Section: Introductionmentioning

confidence: 99%

Multiferroic tunnel junctions and ferroelectric control of magnetic state at interface (invited)

Yin

Raju

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

Articles you may be interested inPrediction of giant magnetoelectric effect in LaMnO3/BaTiO3/SrMnO3 superlattice: The role of n-type SrMnO3/LaMnO3 interface J. Appl. Phys. 116, 074102 (2014) As semiconductor devices reach ever smaller dimensions, the challenge of power dissipation and quantum effect place a serious limit on the future device scaling. Recently, a multiferroic tunnel junction (MFTJ) with a ferroelectric barrier sandwiched between two ferromagnetic electrodes has drawn enormous interest due to its potential applications not only in multi-level data storage but also in electric field controlled spintronics and nanoferronics. Here, we present our investigations on four-level resistance states, giant tunneling electroresistance (TER) due to interfacial magnetoelectric coupling, and ferroelectric control of spin polarized tunneling in MFTJs. Coexistence of large tunneling magnetoresistance and TER has been observed in manganite/(Ba, Sr)TiO 3 /manganite MFTJs at low temperatures and room temperature four-resistance state devices were also obtained. To enhance the TER for potential logic operation with a magnetic memory, La 0.7 Sr 0.3 MnO 3 /BaTiO 3 /La 0.5 Ca 0.5 MnO 3 /La 0.7 Sr 0.3 MnO 3 MFTJs were designed by utilizing a bilayer tunneling barrier in which BaTiO 3 is ferroelectric and La 0.5 Ca 0.5 MnO 3 is close to ferromagnetic metal to antiferromagnetic insulator phase transition. The phase transition occurs when the ferroelectric polarization is reversed, resulting in an increase of TER by two orders of magnitude. Tunneling magnetoresistance can also be controlled by the ferroelectric polarization reversal, indicating strong magnetoelectric coupling at the interface. V C 2015 AIP Publishing LLC.

show abstract

Section: Introductionmentioning

confidence: 99%

Multiferroic tunnel junctions and ferroelectric control of magnetic state at interface (invited)

Yin

Raju

et al. 2015

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…In contrast with metallic spin valves, theoretical models [17,18,19] and experimental evidence [20,21] suggest that in magnetic tunnel junctions the spin torque is a function of voltage and does not depend on Z L (t), the time dependent device resistance, but only on R P . Therefore we assume that the spin torque in MTJ's is given by τ s =h 2e…”

Section: Resultsmentioning

confidence: 99%

“…where V (d, t) is the device voltage [17,18]. Although in general the torque can be a more complicated function of voltage, experiments have shown that at small bias the parallel torque is linear in voltage [20,21].…”

Section: Resultsmentioning

confidence: 99%

Effect of resistance feedback on spin torque-induced switching of nanomagnets

Garzon

Webb

Covington

et al. 2009

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

In large magnetoresistance devices spin torque-induced changes in resistance can produce GHz current and voltage oscillations which can affect magnetization reversal. In addition, capacitive shunting in large resistance devices can further reduce the current, adversely affecting spin torque switching. Here, we simultaneously solve the Landau-Lifshitz-Gilbert equation with spin torque and the transmission line telegrapher's equations to study the effects of resistance feedback and capacitance on magnetization reversal of both spin valves and magnetic tunnel junctions. While for spin valves parallel (P) to anti-parallel (AP) switching is adversely affected by the resistance feedback due to saturation of the spin torque, in low resistance magnetic tunnel junctions P-AP switching is enhanced. We study the effect of resistance feedback on the switching time of MTJ's, and show that magnetization switching is only affected by capacitive shunting in the pF range.

show abstract

“…The angular momentums may be transferred from the electrons of the spin-polarized current to the ferromagnet, giving rise to a switching of magnetization or stable precession of magnetizations [6] that leads to the generation of spin waves [7]. This mechanism of STT was initially proposed by Berger et al [8] and Slonczewski [9] in 1996 and attracted significant interests because of the great potential for direct current-induced spintronic devices [10][11][12]. The role of STT in magnetization switching has been verified by numerous experiments in spin-valve nanopillars [13][14][15], magnetic nanowires [16,17], point contact geometry [18][19][20], and magnetic tunnel junctions [21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Micromagnetic Simulation of Spin Transfer Torque Magnetization Precession Phase Diagram in a Spin-Valve Nanopillar under External Magnetic Fields

Huang

Liu

et al. 2012

ISRN Condensed Matter Physics

View full text Add to dashboard Cite

We investigated spin transfer torque magnetization precession in a nanoscale pillar spin-valve under external magnetic fields using micromagnetic simulation. The phase diagram of the magnetization precession is calculated and categorized into four states according to their characteristics. Of the four states, the precessional state has two different modes: steady precession mode and substeady precession mode. The different modes originate from the dynamic balance between the spin transfer torque and the Gilbert damping torque. Furthermore, we reported the behavior of the temporal evolutions of magnetization components in steady precession mode at the condition of the applied magnetic field using the orbit projection method and explaining perfectly the magnetization components evolution behavior. In addition, a result of a nonuniform magnetization distribution is observed in the free layer due to the excitation of non-uniform mode.

show abstract

Magnetoresistance and spin-transfer torque in magnetic tunnel junctions

Cited by 163 publications

References 96 publications

Multiferroic tunnel junctions and ferroelectric control of magnetic state at interface (invited)

Multiferroic tunnel junctions and ferroelectric control of magnetic state at interface (invited)

Effect of resistance feedback on spin torque-induced switching of nanomagnets

Micromagnetic Simulation of Spin Transfer Torque Magnetization Precession Phase Diagram in a Spin-Valve Nanopillar under External Magnetic Fields

Contact Info

Product

Resources

About