Phenomenological analysis for spin-Seebeck effect in metallic magnets

Uchida, K.; Takahashi, Saburo; Ieda, Jun’ichi; Harii, Kiyonori; Ikeda, Kazuma; Koshibae, Wataru; Maekawa, Sadamichi; Saitoh, Eiji

doi:10.1063/1.3056581

Cited by 39 publications

(34 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, in most of the experiments of current assisted DW depinning in ferromagnetic nanostripes with a notch, the electric current generates important thermal gradients close to the contact pads [6] and also close to the notch, as we will show in this work. These thermal gradients could also affect the movement of the DW [7,8].…”

Section: Introductionmentioning

confidence: 99%

Joule heating in ferromagnetic nanostripes with a notch

et al. 2015

View full text Add to dashboard Cite

The temperature in a ferromagnetic nanostripe with a notch subject to Joule heating has been studied in detail. We first performed an experimental real-time calibration of the temperature versus time as a 100 ns current pulse was injected into a Permalloy nanostripe. This calibration was repeated for different pulse amplitudes and stripe dimensions and the set of experimental curves were fitted with a computer simulation using the Fourier thermal conduction equation. The best fit of these experimental curves was obtained by including the temperature-dependent behavior of the electrical resistivity of the Permalloy and of the thermal conductivity of the substrate (SiO 2 ). Notably, a nonzero interface thermal resistance between the metallic nanostripe and the substrate was also necessary to fit the experimental curves. We found this parameter pivotal to understand our results and the results from previous works. The higher current density in the notch, together with the interface thermal resistance, allows a considerable increase of the temperature in the notch, creating a large horizontal thermal gradient. This gradient, together with the high temperature in the notch and the larger current density close to the edges of the notch, can be very influential in experiments studying the current assisted domain wall motion.

show abstract

Section: Introductionmentioning

confidence: 99%

Joule heating in ferromagnetic nanostripes with a notch

et al. 2015

View full text Add to dashboard Cite

show abstract

“…We note that our definition of S s should be distinguished from the spin Seebeck coefficient defined in ref. 9, where a so-called 'entropy term' was included 23 . We do not include this term in our analysis.…”

mentioning

confidence: 99%

Thermally driven spin injection from a ferromagnet into a non-magnetic metal

et al. 2010

View full text Add to dashboard Cite

Thermally driven spin injection from a ferromagnet into a non-magnetic metal Slachter, A.; Bakker, F. L.; Adam, J-P.; van Wees, B. J.Published in: Nature Physics DOI: 10.1038/NPHYS1767IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document VersionPublisher's PDF, also known as Version of record Publication date: 2010Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Slachter, A., Bakker, F. L., Adam, J-P., & van Wees, B. J. (2010). Thermally driven spin injection from a ferromagnet into a non-magnetic metal. Nature Physics, 6(11), 879-882. https://doi.org/10.1038/NPHYS1767 Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. van WeesCreation, manipulation and detection of spin-polarized carriers are the key elements of spin-based electronics 1,2 . Most practical devices 3-5 use a perpendicular geometry in which the spin currents are accompanied by charge currents. In recent years, new sources of pure spin currents (that is, transport of spin angular momentum without charge currents) have been demonstrated 6-9 and applied 10-12 . Here we demonstrate a conceptually new source of pure spin current driven by the flow of heat across the interface between a ferromagnet and a non-magnetic metal. This spin current is generated because, in a ferromagnet, the Seebeck effect-which describes the generation of a voltage as a result of a temperature gradient-is spin dependent 13,14 . We studied this new source of spin currents experimentally in a non-local lateral geometry and developed a three-dimensional model that describes the heat, charge and spin transport in this geometry, enabling us to quantify this process 15 . We obtain a spin-dependent Seebeck coefficient for Permalloy of −3.8 µV K −1 , suggesting that thermally driven spin injection is a feasible alternative for electrical spin injection in, for example, spin-transfer-torque experiments 16 .The interplay of spin-dependent conductivity and thermoelectricity has been known since half a century ago, when it was used to describe the conventional Seebeck effect of ferromagnetic metals 17 . The discovery of the giant magnetoresistance effect 3 sparked the interest of the community in spin-dependent conductivity and new spin electronics that still exists today 4,5,8,18 . Owing to experimental difficulties in controlling heat flows it was only very recently that thermoelectric spintronics was investigated 19,20 , leading to the new field of spin caloritronics 13 . A relevant example is given in ref. 9, which interpret...

show abstract

“…48 Also, the "entropic" terms in the spin accumulation as introduced in Ref. 30, which would lead to a uniform decay of the spin accumulation across the whole sample, not just at the distances of the spin-diffusion lengths off of the edges, do not arise in our theory.…”

Section: Ferromagnet Placed In a Thermal Gradientmentioning

confidence: 99%

“…In analogy, the spin Seebeck effect describes the generation of spin accumulation in ferromagnets by thermal gradients. The effect was originally observed in the ferromagnetic conductor NiFe, 27,30 where indication of spin accumulation over large length scales (millimeters), independent of the spin-relaxation scales in the ferromagnet, was found. Since it also exists at room temperature, the spin Seebeck phenomenon may have some technological applications.…”

Section: Introductionmentioning

confidence: 96%

“…6 for a junction consisting of Ni 81 Fe 19 (see Sec. III for the corresponding parameters) and Cu (λ sN = 350 nm, σ N = 5.88 × 10 7 1/ m, S N = 1.84 × 10 −6 V/K) with a temperature difference T = T 2 − T 1 = −100 mK between both ends of the junction and the mean temperature T = 300 K. 30,40,49 Figure 7 shows the spin and heat currents for the same system. In Figs.…”

Section: -7mentioning

confidence: 99%

See 1 more Smart Citation

Theory of thermal spin-charge coupling in electronic systems

et al. 2012

View full text Add to dashboard Cite

The interplay between spin transport and thermoelectricity offers several novel ways of generating, manipulating, and detecting nonequilibrium spin in a wide range of materials. Here, we formulate a phenomenological model in the spirit of the standard model of electrical spin injection to describe the electronic mechanism coupling charge, spin, and heat transport and employ the model to analyze several different geometries containing ferromagnetic (F) and nonmagnetic (N) regions: F, F/N, and F/N/F junctions, which are subject to thermal gradients. We present analytical formulas for the spin-accumulation and spin-current profiles in those junctions that are valid for both tunnel and transparent (as well as intermediate) contacts. For F/N junctions, we calculate the thermal spin-injection efficiency and the spin-accumulation-induced nonequilibrium thermopower. We find conditions for countering thermal spin effects in the N region with electrical spin injection. This compensating effect should be particularly useful for distinguishing electronic from other mechanisms of spin injection by thermal gradients. For F/N/F junctions, we analyze the differences in the nonequilibrium thermopower (and chemical potentials) for parallel and antiparallel orientations of the F magnetizations, as evidence and a quantitative measure of the spin accumulation in N. Furthermore, we study the Peltier and spin Peltier effects in F/N and F/N/F junctions and present analytical formulas for the heat evolution at the interfaces of isothermal junctions.

show abstract

Phenomenological analysis for spin-Seebeck effect in metallic magnets

Cited by 39 publications

References 18 publications

Joule heating in ferromagnetic nanostripes with a notch

Joule heating in ferromagnetic nanostripes with a notch

Thermally driven spin injection from a ferromagnet into a non-magnetic metal

Theory of thermal spin-charge coupling in electronic systems

Contact Info

Product

Resources

About