Spin-dependent Seebeck effect in non-local spin valve devices

Erekhinsky, Mikhail; Casanova, Fèlix; Schuller, Iván K.; Sharoni, Amos

doi:10.1063/1.4717752

Cited by 58 publications

(57 citation statements)

References 27 publications

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“…The difference between P and AP is commonly labeled R s and is a measure of the accumulation and diffusion of spins within the NM. It is widely observed that the temperature dependence of R s within Cu/Py LSVs is nonmonotonic, with a peak around 30 K [11][12][13][14][15]. A similar behavior is found in LSVs containing other materials [15][16][17].…”

supporting

confidence: 59%

Spin relaxation through Kondo scattering in Cu/Py lateral spin valves

et al. 2015

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The temperature dependence of the spin diffusion length typically reflects the scattering mechanism responsible for spin relaxation. Within nonmagnetic metals it is reasonable to expect the Elliot-Yafet mechanism to play a role and thus the temperature dependence of the spin diffusion length might be inversely proportional to resistivity. In lateral spin valves, measurements have found that at low temperatures the spin diffusion length unexpectedly decreases. By measuring the transport properties of lateral Py/Cu/Py spin valves, fabricated from Cu with magnetic impurities of <1 ppm and ∼ 4 ppm, we extract a spin diffusion length which shows this suppression below 30 K only in the presence of the Kondo effect. We have calculated the spin-relaxation rate and isolated the contribution from magnetic impurities. We find the spin-flip probability of a magnetic impurity to be 34%. Our analysis demonstrates the dominant role of Kondo scattering in spin relaxation, even in low concentrations of order 1 ppm, and hence illustrates its importance to the reduction in spin diffusion length observed by ourselves and others.

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confidence: 59%

Spin relaxation through Kondo scattering in Cu/Py lateral spin valves

et al. 2015

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“…Recently, thermal effects on the NLSV have proven a critical area of study, with some authors suggesting that the dominant physics driving the background resistance of the NLSV originates in thermoelectric effects [10][11][12], and others observing that significant Joule heating plays an important role in spin injection [13,14]. A few groups have even shown that spin accumulation and transport in a metallic NLSV is possible by driving heat current, rather than charge current [13,[15][16][17][18][19][20]. Such a thermal injection is shown schematically in Fig.…”

Section: Introductionmentioning

confidence: 99%

Thermal spin injection and interface insensitivity in permalloy/aluminum metallic nonlocal spin valves

2016

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We present measurements of thermal and electrical spin injection in nanoscale metallic non-local spin valve (NLSV) structures. Informed by measurements of the Seebeck coefficient and thermal conductivity of representative films made using a micromachined Si-N thermal isolation platform, we use simple analytical and finite element thermal models to determine limits on the thermal gradient driving thermal spin injection and calculate the spin dependent Seebeck coefficient to be −0.5 µV/K < S s < −1.6 µV/K. This is comparable in terms of the fraction of the absolute Seebeck coefficient to previous results, despite dramatically smaller electrical spin injection signals.Since the small electrical spin signals are likely caused by interfacial effects, we conclude that thermal spin injection is less sensitive to the FM/NM interface, and possibly benefits from a layer of oxidized ferromagnet, which further stimulates interest in thermal spin injection for applications in sensors and pure spin current sources.1 arXiv:1602.03859v2 [cond-mat.mes-hall]

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“…Recently, heat has been used as a new approach to control the spin in ferromagnetic/nonmagnetic hybrid nanostructures. [6][7][8][9][10][11][12][13][14] A representative and fascinating phenomenon is thermal spin injection, in which excess heat can be used to produce spin current because of the spin-dependent Seebeck coefficient. [7][8][9] Until now, thermally driven spin injection has only been demonstrated using conventional ferromagnetic metals such as permalloy (Py) 7 and cobalt.…”

Section: Introductionmentioning

confidence: 99%

Efficient thermal spin injection using CoFeAl nanowire

Itoh

Kimura

2014

NPG Asia Mater

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Nanoelectronic devices based on electron spin can overcome the physical limitations of the present semiconductor technology because of their low power consumption while exploiting the spin degree of freedom of electrons. Although enhancing the efficiency of generation of the spin current is imperative and a primary issue for the practical application of spin-based electronics, seamless device integration with the conventional complementary metal-oxide semiconductor technology is another important milestone for developing spin-based nanoelectronics. In particular, the preparation of nanosized, magnetic, multilayered structures with electrical connections to individual complementary metal-oxide semiconductor circuits significantly complicates the fabrication procedure of nanoelectronic devices. Thermal spin injection, which is a recently discovered unique characteristic of spin current, may be an innovative method for simplifying device integration without the need for electricity, namely wireless spintronics. However, the feasibility of using the thermal spin injection method is poor because of its extremely low-generation efficiency. Here, we demonstrate that a highly spin-polarized, ferromagnetic CoFeAl electrode with a favorable band structure has excellent properties for thermal spin injection. The spin-dependent Seebeck coefficient is approximately 70 lV K À1 , which facilitates highly efficient generation of the spin current from heat. The heat generates approximately 100 times more spin voltage than a conventional ferromagnetic injector at room temperature. This innovative demonstration may open a new route for spin-device integration and its applications.

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Spin-dependent Seebeck effect in non-local spin valve devices

Cited by 58 publications

References 27 publications

Spin relaxation through Kondo scattering in Cu/Py lateral spin valves

Spin relaxation through Kondo scattering in Cu/Py lateral spin valves

Thermal spin injection and interface insensitivity in permalloy/aluminum metallic nonlocal spin valves

Efficient thermal spin injection using CoFeAl nanowire

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