Spin-charge conversion in NiMnSb Heusler alloy films

Half-metallic Heusler alloys are attracting considerable attention because of their unique half-metallic band structures, which exhibit high spin polarization and yield huge magnetoresistance ratios. Besides serving as ferromagnetic electrodes, Heusler alloys also have the potential to host spin-charge conversion. Here, we report on the spin-charge conversion effect in the prototypical Heusler alloy NiMnSb. An unusual charge signal was observed with a sign change at low temperature, which can be manipulated by film thickness and ordering structure. It is found that the spin-charge conversion has two contributions. First, the interfacial contribution causes a negative voltage signal, which is almost constant versus temperature. The second contribution is temperature dependent because it is dominated by minority states due to thermally excited magnons in the bulk part of the film. This work provides a pathway for the manipulation of spin-charge conversion in ferromagnetic metals by interface-bulk engineering for spintronic devices.

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Tunnel magnetoresistance effect and magnetic damping in half-metallic Heusler alloys

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2011.0011 ◽

2011 ◽

Vol 369 (1948) ◽

pp. 3037-3053 ◽

Cited By ~ 20

Author(s):

M. Oogane ◽

S. Mizukami

Keyword(s):

Spin Polarization ◽

High Spin ◽

Heusler Alloy ◽

Heusler Alloys ◽

Magnetoresistance Effect ◽

Half Metallicity ◽

Half Metallic ◽

Tunnel Magnetoresistance ◽

Magnetic Damping ◽

High Spin Polarization

Some full-Heusler alloys, such as Co 2 MnSi and Co 2 MnGe, are expected to be half-metallic ferromagnetic material, which has complete spin polarization. They are the most promising materials for realizing half-metallicity at room temperature owing to their high Curie temperature. We demonstrate a huge tunnel magnetoresistance effect in a magnetic tunnel junction using a Co 2 MnSi Heusler alloy electrode. This result proves high spin polarization of the Heusler alloy. We also demonstrate a small magnetic damping constant in Co 2 FeAl epitaxial film. The very high spin polarization and small magnetic constant of Heusler alloys will be a great advantage for future spintronic device applications.

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Use of Half Metallic Heusler Alloys in CoFeB/MgO/Heusler Alloy Tunnel Junctions

IEEE Transactions on Magnetics ◽

10.1109/tmag.2013.2244584 ◽

2013 ◽

Vol 49 (7) ◽

pp. 4379-4382 ◽

Cited By ~ 9

Author(s):

P. J. Chen ◽

G. Feng ◽

R. D. Shull

Keyword(s):

Heusler Alloy ◽

Tunnel Junctions ◽

Heusler Alloys ◽

Half Metallic

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Electronic and Magnetic Properties of Half Metallic Heusler Alloy Co2mnsi: A First-Principles Study

Himalayan Physics ◽

10.3126/hj.v6i0.18354 ◽

2017 ◽

pp. 31-36

Author(s):

Prakash Sharma ◽

Gopi Chandra Kaphle

Keyword(s):

Magnetic Properties ◽

Magnetic Moment ◽

Heusler Alloy ◽

Density Functional ◽

Heusler Alloys ◽

Tight Binding ◽

Lattice Parameter ◽

Half Metallic ◽

Electronic And Magnetic Properties ◽

Sphere Approximation

Heusler alloys have been of great interest because of their application in the field of modern technological word. Electronic and magnetic properties of Co, Mn, Si and the Heusler alloy Co2MnSi have been studied using Density functional theory based Tight Binding Linear Muffin Tin Orbital with Atomic Sphere Approximation (TB-LMTO-ASA) approach. From the calculation lattice parameter of optimized structure of Co, Mn, Si and Co2MnSi are found to be 2.52A0 , 3.49A0 , 5.50A0 , 5.53A0 respectively. Band structure calculations show that Co and Mn are metallic, Si as semi-conducting while the Heusler alloy Co2MnSi as half-metallic in nature with band gap 0.29eV. The charge density plot indicates major bonds in Co2MnSi are ionic in nature. Magnetic property has been studied using the density of states (DOS), indicating that Co and Co2MnSi are magnetic with magnetic moment 2.85μB and 4.91μB respectively. The contribution of orbitals in band, DOS and magnetic moment are due to d-orbitals of Co and Mn and little from s and p-orbital of Si in Co2MnSi.The Himalayan Physics Vol. 6 & 7, April 2017 (31-36)

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Investigation of high spin-polarization, magnetic, electronic and half-metallic properties in RuMn2Ge and RuMn2Sb Heusler alloys

Materials Science and Engineering B ◽

10.1016/j.mseb.2014.11.009 ◽

2015 ◽

Vol 193 ◽

pp. 70-75 ◽

Cited By ~ 29

Author(s):

Dinesh C. Gupta ◽

Idris Hamid Bhat

Keyword(s):

Spin Polarization ◽

High Spin ◽

Heusler Alloys ◽

Half Metallic ◽

High Spin Polarization

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Magnetoelastic interactions and magnetic damping in Co2Fe0.4Mn0.6Si and Co2FeGa0.5Ge0.5 Heusler alloys thin films for spintronic applications

Scientific Reports ◽

10.1038/s41598-021-87205-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

O. M. Chumak ◽

A. Pacewicz ◽

A. Lynnyk ◽

B. Salski ◽

T. Yamamoto ◽

...

Keyword(s):

Thin Films ◽

Magnetic Properties ◽

Layer Thickness ◽

Heusler Alloys ◽

Magnetic Layer ◽

Spin Pumping ◽

Magnetic Damping ◽

Spintronic Devices ◽

Damping Parameter ◽

High Spin Polarization

AbstractCo2Fe0.4Mn0.6Si (CFMS) and Co2FeGa0.5Ge0.5 (CFGG) Heusler alloys are among the most promising thin film materials for spintronic devices due to a high spin polarization, low magnetic damping and giant/tunneling magnetoresistance ratios. Despite numerous investigations of Heusler alloys magnetic properties performed up to now, magnetoelastic effects in these materials remain not fully understood; due to quite rare studies of correlations between magnetoelastic and other magnetic properties, such as magnetic dissipation or magnetic anisotropy. In this research we have investigated epitaxial CFMS and CFGG Heusler alloys thin films of thickness in the range of 15–50 nm. We have determined the magnetoelastic tensor components and magnetic damping parameters as a function of the magnetic layer thickness. Magnetic damping measurements revealed the existence of non-Gilbert dissipation related contributions, including two-magnon scattering and spin pumping phenomena. Magnetoelastic constant B11 values and the effective magnetic damping parameter αeff values were found to be in the range of − 6 to 30 × 106 erg/cm3 and between 1 and 12 × 10–3, respectively. The values of saturation magnetostriction λS for CFMS Heusler alloy thin films were also obtained using the strain modulated ferromagnetic resonance technique. The correlation between αeff and B11, depending on magnetic layer thickness was determined based on the performed investigations of the above mentioned magnetic properties.

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Prediction of electronic and half metallic properties of Mn2YSn (Y = Mo, Nb, Zr) Heusler alloys

Condensed Matter Physics ◽

10.5488/cmp.24.13703 ◽

2021 ◽

Vol 24 (1) ◽

pp. 13703

Author(s):

S. Zeffane ◽

M. Sayah ◽

F. Dahmane ◽

M. Mokhtari ◽

L. Zekri ◽

...

Keyword(s):

Density Functional ◽

Magnetic Moments ◽

Heusler Alloys ◽

Type Structure ◽

Generalized Gradient ◽

Functional Theory ◽

Half Metallic ◽

Spintronic Devices ◽

Lattice Constants ◽

Good Agreement

We investigate the structural, electronic and magnetic properties of the full Heusler compounds Mn2YSn (Y = Mo, Nb, Zr) by first- principles density functional theory using the generalized gradient approximation. It is found that the calculated lattice constants are in good agreement with the theoretical values. We observe that the Cu2MnAl-type structure is more stable than the Hg2CuTi type. The calculated total magnetic moments of Mn2NbSn and Mn2ZrSn are 1 μB and 2 μB at the equilibrium lattice constant of 6.18 Å and 6.31 Å, respectively, for the Cu2MnAl-type structure. Mn2MoSn have a metallic character in both Hg2CuTi and Cu2MnAl type structures. The total spin magnetic moment obeys the Slater-Pauling rule. Half-metal exhibits 100% spin polarization at the Fermi level. Thus, these alloys are promising magnetic candidates in spintronic devices.

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Theoretical Study of the Electronic Properties of X2YZ (X = Fe, Co; Y = Zr, Mo; Z = Ge, Sb) Ternary Heusler: Abinitio Study

Annals of West University of Timisoara - Physics ◽

10.2478/awutp-2020-0001 ◽

2020 ◽

Vol 62 (1) ◽

pp. 1-14

Author(s):

A. Maafa ◽

H. Rozale ◽

A. Oughilas ◽

A. Boubaça ◽

A. Amar ◽

...

Keyword(s):

Density Functional ◽

Heusler Alloys ◽

Metallic Behavior ◽

Functional Theory ◽

Half Metallic ◽

Spintronic Devices ◽

Half Metals ◽

Potential Applications ◽

Small Band ◽

Moderate Range

AbstractIn the purpose of exploring new Heusler alloys with different magnetic applications, we have employed first principles calculations method within density functional theory. After checking the structural stability of X2YZ Heusler alloys (X = Fe, Co; Y =Zr, Mo and Z = Ge, Sb), we found that Cu2MnAl type structure is more favorable for most compounds except for X2MoGe and Co2MoSb, were the Hg2CuTi structure is energetically more stable. The trends in magnetic and electronic structures can be predicted by the structure types as well as the different kinds of hybridizations between the constituents. Among the two series only two compounds were identified to be true half metals with potential applications in spintronic devices. While one compound was classified as a nonmagnetic semiconductor with a small band gap. For the rest of materials, we found that the metallic behavior is dominant. These materials show possible interesting features in technical applications as well. The effect of distortion on the magnetic properties of Co2ZrGe and Fe2ZrSb showed that the half metallic character was preserved within a moderate range of volume changes, which makes it possible to grow these materials as thin films with modern techniques.

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Electronic Structure and Spin-Injection of Co-Based Heusler Alloy/ Semiconductor Junctions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.470.54 ◽

2011 ◽

Vol 470 ◽

pp. 54-59

Author(s):

Hiroyoshi Itoh ◽

Syuta Honda ◽

Junichiro Inoue

Keyword(s):

Electronic Structure ◽

Heusler Alloy ◽

Spin Injection ◽

Magnetic Moments ◽

Heusler Alloys ◽

Growth Direction ◽

Layer By Layer ◽

Half Metallicity ◽

Half Metallic ◽

Layer Stacking

The electronic structures of Co-based Heusler alloys with nonstoichiometric atomic compositions as well as those at the interface of semiconductor junctions are investigated using first principles band calculations. It is shown that the electronic structure of a Co-based Heusler alloy is half-metallic, even for nonstoichiometric but Co-rich compositions, whereas the half-metallicity is lost for Co-poor compositions. It is also shown that magnetic moments at the interface of Co2MnSi/ Si junctions are sensitive to the growth direction and interface structure of the junctions. Efficient spin-injection into Si can be achieved by using a (111)-oriented Co-rich Heusler alloy and controlling the layer-by-layer stacking sequence at the interface.

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Structural, Electronic and Magnetic Properties of XYZ Type Half-Heusler Alloys

Journal of Nepal Physical Society ◽

10.3126/jnphyssoc.v5i1.26938 ◽

2019 ◽

Vol 5 (1) ◽

pp. 97-102

Author(s):

R. Dahal ◽

G. C. Kaphle

Keyword(s):

Magnetic Moment ◽

Density Functional ◽

Heusler Alloys ◽

Tight Binding ◽

Functional Materials ◽

Lattice Parameter ◽

Half Metallic ◽

Spintronic Devices ◽

Sphere Approximation ◽

Equilibrium Lattice Parameter

The spintronic devices have played an important role in modern technological era. Heusler alloys have attracted lot of interest in spintronic applications due to their half-metallic properties predicted by band structure calculations. We investigate the electronic, magnetic and structural properties of half-Heusleralloys FeMnGe and CoMnSb using first principles based density functional theory (DFT) implemented on Tight Binding Linear Muffin-Tin Orbital within Atomic Sphere Approximation (TB-LMTO-ASA) code. The calculation reveal that CoMnSb and FeMnGe are half-metallic Ferro-magnet in nature of with magnetic moment 1.00 μB and 2.99 μB per formula unit at equilibrium lattice parameter respectively. The magnetic moment mainly originates from the strong spin polarization of d electrons of X atom and partial contribution of p electrons of Y atom. The half metallic gap of FeMnGe and CoMnSb is found to be 0.38 eV and 0.95 eV respectively. This shows that these alloys are very promising spintronic functional materials.

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