Anisotropic magnetoresistance in ferromagnetic 3d alloys

McGuire, T. R.; Potter, Robert I.

doi:10.1109/tmag.1975.1058782

Cited by 1,723 publications

(1,271 citation statements)

References 68 publications

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“…Within the Boltzmann equation approach, such calculations are usually performed by using the relaxation-time approximation in which the transport relaxation time is calculated from the scattering amplitudes without fully taking into account the asymmetries. 30,34 This approach was improved in Ref. 53 by introducing the perpendicular relaxation time Ќ .…”

Section: Amr In Rashba Systemsmentioning

confidence: 99%

“…The change in the resistance as a function of the magnetization direction relative to the current or crystallographic direction is called the AMR effect. The microscopic origin of the AMR in transition-metal ferromagnets is still elusive [28][29][30][31] and detailed calculations require consideration of complicated band structures. 32,33 A relatively simple host band structure in the DMS ferromagnets provides a pos-sibility for performing detailed microscopic calculations based on simple physical models.…”

Section: Introductionmentioning

confidence: 99%

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Transport theory for disordered multiple-band systems: Anomalous Hall effect and anisotropic magnetoresistance

et al. 2009

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We present a study of transport in multiple-band noninteracting Fermi metallic systems based on the Keldysh formalism and the self-consistent T-matrix approximation ͑TMA͒ taking into account the effects of Berry curvature due to spin-orbit coupling. We apply this formalism to a Rashba two-dimensional electron-gas ferromagnet and calculate the anomalous Hall effect ͑AHE͒ and anisotropic magnetoresistance ͑AMR͒. The numerical calculations of the AHE reproduce analytical results in the metallic regime revealing the crossover between the skew-scattering mechanism dominating in the clean systems and intrinsic mechanism dominating in the moderately dirty systems. As we increase the disorder further, the AHE starts to diminish due to the spectral broadening of the quasiparticles. Although for certain parameters this reduction of the AHE can be approximated as xy ϳ xx , with varying around 1.6, this is found not to be true in general as xy can go through a change in sign as a function of disorder strength in some cases. Furthermore, the disordered region consistent with the TMA is relatively narrow and a theory with a wider range of applicability in strong disorder limit is called for. By considering the higher order skew-scattering processes, we resolve some discrepancies between the AHE results obtained by using the Keldysh, Kubo, and Boltzmann approaches. We also show that similar higher order processes are important for the AMR when the nonvertex and vertex parts cancel each other. We calculate the AMR in anisotropic systems properly taking into account the anisotropy of the nonequilibrium distribution function. These calculations confirm recent findings on the unreliability of common approximations to the Boltzmann equation.

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Section: Amr In Rashba Systemsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Transport theory for disordered multiple-band systems: Anomalous Hall effect and anisotropic magnetoresistance

et al. 2009

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“…The last mechanism, for example, lies at the heart of the s-d model of AMR in transition metals 6 where isotropic and spin-independent scattering operators have been assumed. 19,20 The anisotropy arises due to the competition of SOI and magnetization which splits the five d states according to l M , their angular momentum projection along ê M . These states play the role of ͉z k Ј n Ј ͘ in Eq.…”

Section: A Origins Of Anisotropymentioning

confidence: 99%

“…This analysis is our main result together with the detailed explanation of the AMR sign in ͑Ga,Mn͒As ͑resistance parallel to magnetization is smaller than perpendicular to magnetization͒ which is observed experimentally 8,9,[12][13][14][15][16][17][18] and is opposite to most magnetic metals. 19,20 The results in Sec. IV include analytically evaluated anisotropic conductivity on several levels of model complexity, and the most simplified model allows to clearly identify the physical mechanism that determines the sign of the AMR in ͑Ga,Mn͒As.…”

Section: Introductionmentioning

confidence: 97%

Microscopic mechanism of the noncrystalline anisotropic magnetoresistance in (Ga,Mn)As

et al. 2009

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Starting with a microscopic model based on the Kohn-Luttinger Hamiltonian and kinetic p-d exchange combined with Boltzmann formula for conductivity we identify the scattering from magnetic Mn combined with the strong spin-orbit interaction of the GaAs valence band as the dominant mechanism of the anisotropic magnetoresistance ͑AMR͒ in ͑Ga,Mn͒As. This fact allows to construct a simple analytical model of the AMR consisting of two heavy-hole bands whose charge carriers are scattered on the impurity potential of the Mn atoms. The model predicts the correct sign of the AMR ͑resistivity parallel to magnetization is smaller than perpendicular to magnetization͒ and identifies its origin arising from the destructive interference between electric and magnetic part of the scattering potential of magnetic ionized Mn acceptors when the carriers move parallel to the magnetization.

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“…The ordinary magnetoresistance in bulk metals is generally a few percent. 1 In contrast to bulk metals, Baibich et al 2 discovered giant magnetoresistance (GMR) in two dimensional Fe/Cr magnetic superlattices, where MR can be as large as 60%. Since then, intense interest has arisen due to potential industrial applications, and GMR was observed in more magnetic/non-magnetic/magnetic heterostructures.…”

Section: Introductionmentioning

confidence: 99%

Correlations of crystallographic defects and anisotropy with magnetotransport properties inFexTaS2single crystals (0.23≤x≤0.35)

et al. 2016

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Very large magnetoresistance discovered in single crystals of the ferromagnetic Fe-intercalated transition metal dichalcogenide, Fe0.28TaS2 was attributed to the deviation of the Fe concentration from commensurate values (x = 1/4 or 1/3), which caused magnetic moment misalignments. Here we report a study of FexTaS2 crystals with 0.23 ≤ x ≤ 0.35, demonstrating that crystallographic defects lead to spin disorder, which correlates with magneto-transport properties such as switching magnetic field HS, magnetoresistance MR, and even zero-field resistivity ρ0 and temperature coefficient A in ρ(T ) = ρ0 + AT 2 : The ordering temperature TC and Weiss temperature θW are maximized at the superstructure composition x = 1/4, while Hs, MR, ρ0, and A are minimum. Conversely, at a composition intermediate between the superstructure compositions x = 1/4 and 1/3, the corresponding magneto-transport properties reach local maxima.

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Anisotropic magnetoresistance in ferromagnetic 3d alloys

Cited by 1,723 publications

References 68 publications

Transport theory for disordered multiple-band systems: Anomalous Hall effect and anisotropic magnetoresistance

Transport theory for disordered multiple-band systems: Anomalous Hall effect and anisotropic magnetoresistance

Microscopic mechanism of the noncrystalline anisotropic magnetoresistance in (Ga,Mn)As

Correlations of crystallographic defects and anisotropy with magnetotransport properties inFexTaS2single crystals (0.23≤x≤0.35)

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