MnGa-based fully perpendicular magnetic tunnel junctions with ultrathin Co2MnSi interlayers

Mao, Shipeng; Lu, Jun; Zhao, Xupeng; Wang, Xiao Li; Wei, Dahai; Liu, Jian; Xia, Jian‐Bai; Zhao, Jianhua

doi:10.1038/srep43064

Cited by 35 publications

(12 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their integration into MTJs is a current focus of study for several groups for exactly this reason 38–40 . However, devices based on these compounds display a non-trivial TMR bias dependence, which can be non-monotonic or even change sign as function of the applied voltage 39–41 . The complicated bias dependence of the TMR should be taken into account to enable real world devices based on such materials, and may even explain why efforts to observe magnetization dynamics have been unsuccessful thus far.…”

Section: Resultsmentioning

confidence: 99%

Tunnel magnetoresistance angular and bias dependence enabling tuneable wireless communication

Kowalska

Fukushima

Sluka

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Spin-transfer torques (STTs) can be exploited in order to manipulate the magnetic moments of nanomagnets, thus allowing for new consumer-oriented devices to be designed. Of particular interest here are tuneable radio-frequency (RF) oscillators for wireless communication. Currently, the structure that maximizes the output power is an Fe/MgO/Fe-type magnetic tunnel junction (MTJ) with a fixed layer magnetized in the plane of the layers and a free layer magnetized perpendicular to the plane. This structure allows for most of the tunnel magnetoresistance (TMR) to be converted into output power. Here, we experimentally and theoretically demonstrate that the main mechanism sustaining steady-state precession in such structures is the angular dependence of the magnetoresistance. The TMR of such devices is known to exhibit a broken-linear dependence versus the applied bias. Our results show that the TMR bias dependence effectively quenches spin-transfer-driven precession and introduces a non-monotonic frequency dependence at high applied currents. This has an impact on devices seeking to work in the ‘THz gap’ due to their non-trivial TMR bias dependences.

show abstract

Section: Resultsmentioning

confidence: 99%

Tunnel magnetoresistance angular and bias dependence enabling tuneable wireless communication

Kowalska

Fukushima

Sluka

et al. 2019

Sci Rep

View full text Add to dashboard Cite

show abstract

“…The TMR ratio has then been improved by tailoring the interface using Co to be 40% at RT for the MTJ, consisting of Mn 0.62 Ga 0.38 (30)/Mg (0.4)/ MgO (1.8)/CoFeB (1.2) (thickness in nm) [315,316]. Similar efforts have been devoted on polycrystalline MTJ consisting of Mn 3 Ge/MgO/ CoFeB, which shows a negative TMR ratio of -35 and -75% at 300 and 3 K, respectively, and low RA of 10 Ω•µm 2 [317].…”

Section: Perpendicular Magnetic Anisotropy (I) Binary Heusler Alloysmentioning

confidence: 99%

Heusler alloys for spintronic devices: review on recent development and future perspectives

Elphick

Frost

Samiepour

et al. 2021

Science and Technology of Advanced Materials

255

View full text Add to dashboard Cite

Heusler alloys are theoretically predicted to become half-metals at room temperature (RT). The advantages of using these alloys are good lattice matching with major substrates, high Curie temperature above RT and intermetallic controllability for spin density of states at the Fermi energy level. The alloys are categorised into half- and full-Heusler alloys depending upon the crystalline structures, each being discussed both experimentally and theoretically. Fundamental properties of ferromagnetic Heusler alloys are described. Both structural and magnetic characterisations on an atomic scale are typically carried out in order to prove the half-metallicity at RT. Atomic ordering in the films is directly observed by X-ray diffraction and is also indirectly probed via the temperature dependence of electrical resistivity. Element specific magnetic moments and spin polarisation of the Heusler alloy films are directly measured using X-ray magnetic circular dichroism and Andreev reflection, respectively. By employing these ferromagnetic alloy films in a spintronic device, efficient spin injection into a non-magnetic material and large magnetoresistance are also discussed. Fundamental properties of antiferromagnetic Heusler alloys are then described. Both structural and magnetic characterisations on an atomic scale are shown. Atomic ordering in the Heusler alloy films is indirectly measured by the temperature dependence of electrical resistivity. Antiferromagnetic configurations are directly imaged by X-ray magnetic linear dichroism and polarised neutron reflection. The applications of the antiferromagnetic Heusler alloy films are also explained. The other non-magnetic Heusler alloys are listed. A brief summary is provided at the end of this review.

show abstract

“…Among several kinds of Co-based Heusler compounds, Co 2 MnSi was indeed identified to show the highest interfacial AFM coupling strength with D0 22 -MnGa. The pMTJ of L1 0 -MnGa-MgO with the Co 2 MnSi as an interlayer was demonstrated to a distinct TMR ratio of 65% at 10 K 27 . In such a coupled composite, the Co 2 MnSi as the high spin-polarized magnetic layer acts as spin-polarizer and the MnGa alloy as the hard PMA layer maintains the thermal stability.…”

Section: Introductionmentioning

confidence: 96%

Structural, electronic and magnetic properties of MnxGa/Co2MnSi (x = 1, 3) bilayers

Chen

Wang

Cheng

et al. 2018

Sci Rep

View full text Add to dashboard Cite

Directly coupled hard and soft ferromagnets were popularly used as the hybridized electrodes to enhance tunnel magnetoresistance (TMR) ratio in the perpendicular magnetic tunnel junction (pMTJ). In this paper, we employ the density functional theory (DFT) with general gradient approximation (GGA) to investigate the interfacial structure and magnetic behavior of tetragonal Heusler-type MnGa (MG)/L21-Co2MnSi (CMS) Heusler alloy bilayers with the MnGa being D022-MnGa alloy (Mn3Ga) and L10-MnGa alloy (MnGa). The MM-MS_B interface with the bridge (B) connection of MnMn termination (MM) of D022- and L10-MnGa layers to MnSi termination (MS) of CMS layers is found to be most stable in the energy point of view. Also, a strong antiferromagnetic coupling and relatively higher spin polarization can be observed in the MM-MS_B interface. Further, a remarkable potential difference to derive electrons to transfer from MG layer to CMS layer appears at the interface. These theoretical results indicate that the MG/CMS bilayers are promising candidates as coupled composites, and moreover, the D022-MG/CMS bilayer is better than L10-MG/CMS bilayer due to its larger spin polarization and built-in field at the interface.

show abstract

MnGa-based fully perpendicular magnetic tunnel junctions with ultrathin Co2MnSi interlayers

Cited by 35 publications

References 34 publications

Tunnel magnetoresistance angular and bias dependence enabling tuneable wireless communication

Tunnel magnetoresistance angular and bias dependence enabling tuneable wireless communication

Heusler alloys for spintronic devices: review on recent development and future perspectives

Structural, electronic and magnetic properties of MnxGa/Co2MnSi (x = 1, 3) bilayers

Contact Info

Product

Resources

About