Electrical and thermal transport in single nickel nanowire

Ou, M. N.; Yang, Tzong Jer; Harutyunyan, Syuzanna R.; Chen, Y. Y.; Chen, C. D.; Lai, Soon Onn

doi:10.1063/1.2839572

Cited by 121 publications

(124 citation statements)

References 23 publications

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“…Drawing any conclusions about the absolute coercive field strength would be elusive, because only one nanowire of each kind was measured in this case and the switching field distribution of single wires spread on a wafer can be surprisingly large due to defects and irregularities [14]. The nanowires show linear, metallic R vs T behaviors with residual resistivity ratios of (300 )/ (2 ) ≈ 4.5, which is a notably high value for electrodeposited, ferromagnetic nanowires [27,36,59,60], indicating a good sample quality (see supporting information).…”

Section: Properties Of Individual Nanomagnetsmentioning

confidence: 99%

Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition

Sergelius¹,

Lee²,

Fruchart³

et al. 2017

Nanotechnology

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Segmented magnetic nanowires are a promising route for the development of three dimensional data storage techniques. Such devices require a control of the coercive field and the coupling mechanisms between individual magnetic elements. In our study, we investigate electrodeposited nanomagnets within host templates using vibrating sample magnetometry and observe a strong dependence between nanowire length and coercive field (25 nm to 5 µm) and diameter (25 nm to 45 nm). A transition from a magnetization reversal through coherent rotation to domain wall propagation is observed at an aspect ratio of approximately 2. Our results are further reinforced via micromagnetic simulations and angle dependent hysteresis loops. The found behavior is exploited to create nanowires consisting of a fixed and a free segment in a spin-valve like structure. The wires are released from the membrane and electrically contacted, displaying a giant magnetoresistance effect that is attributed to individual switching of the coupled nanomagnets. We develop a simple analytical model to describe the observed switching phenomena and to predict stable and unstable regimes in coupled nanomagnets of certain geometries.-2 - INTRODUCTIONIn the investigation of nanomagnet assemblies, the focus has mainly been on lithographicallypatterned, planar structures, which can be used as logic devices capable of executing Boolean logic operations [1][2][3][4][5][6][7][8]. Often applications are sought within high density recording, bit patterned media [9][10][11][12] or MRAM devices [1,13], however since the bit size of modern hard disk drives (approx. 20x20 nm²) is already lower than what is achievable with most lithography techniques [14], potential use is limited. Therefore, the use of the third dimension is an appealing approach. Studies on alternating, vertical stacks of magnetic and non-magnetic materials have already been published, in which a three dimensional shift register is investigated, that is capable of storing and shifting several bits of information as solitons within a single column [15][16][17][18][19]. These shift registers are coupled via RKKY interaction and its oscillatory nature allows for an additional degree of freedom in the design of the device, but as a drawback the samples are very demanding with regard to sample quality and purity. A soliton, which is the bearer of information, is a magnetic frustration within a 1D chain of magnetic moments. It is thinkable to induce such a soliton using dipolar coupling instead of RKKY, simply by magnetizing two nanomagnets in the same direction and placing them next to each other (transversal soliton [20]). Another possibility would be to magnetize them in opposing direction and place them in a head-to-head or tail-to-tail configuration (longitudinal soliton, Figure 1). The coupling strength is then defined by the material properties and the distance of both nanomagnets. Such kinds of nanowires can be synthesized within porous anodic aluminum oxide (AAO) templates [21-23] using electro...

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Section: Properties Of Individual Nanomagnetsmentioning

confidence: 99%

Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition

Sergelius¹,

Lee²,

Fruchart³

et al. 2017

Nanotechnology

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“…16 Existing investigations of thermal conductivity in single metallic nanowires suggest either excellent agreement with WF, 17 or violations indicating presence of a significant phonon thermal conductivity. 18 Finally, a number of measurements on suspended Measured values of thermal conductivity, particularly for transition metal thin films, are essential for better understanding of a wide range of spintronic and spincaloritronic effects including magneto-Seebeck effects in magnetic tunnel junctions, [19][20][21][22] joule heating in nanowires 23 , thermal spin torques [24][25][26][27] , the longitudinal spin Seebeck effect, [28][29][30] and spin-dependent Seebeck and Peltier effects.…”

Section: -13mentioning

confidence: 99%

Thermal and electrical conductivity of approximately 100-nm permalloy, Ni, Co, Al, and Cu films and examination of the Wiedemann-Franz Law

et al. 2015

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We present measurements of thermal and electrical conductivity of polycrystalline permalloy (Ni-Fe), aluminum, copper, cobalt, and nickel thin films with thickness < 200 nm. A micromachined silicon-nitride membrane thermal isolation platform allows measurements of both transport properties on a single film and an accurate probe of the Wiedemann-Franz (WF) law expected to relate the two. Through careful elimination of possible effects of surface scattering of phonons in the supporting membrane, we find excellent agreement with WF in a thin Ni-Fe film over nearly the entire temperature range from 77 to 325 K. All other materials studied here deviate somewhat from the WF prediction of electronic thermal conductivity with a Lorenz number, L, suppressed from the free-electron value by 10 − 20%. For Al and Cu we compare the results to predictions of the theoretical expression for the Lorenz number as a function of T . This comparison indicates two different types of deviation from expected behavior. In the Cu film, a higher than expected L at lower T indicates an additional thermal conduction mechanism, while at higher T lower than expected values suggests an additional inelastic scattering mechanism for electrons. We suggest the additional low T L indicates a phonon contribution to thermal conductivity, and consider increased electron-phonon scattering at grain boundaries or surfaces to explain the high T reduction in L.

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“…This kind of phenomenon also has been observed in gold and platinum nanofilms, 4,19,20 nickel nanowire 21 and alloys 22 . The reduced thermal conductivity was attributed to the increased scatterings of heat carriers from structural imperfection and the contribution of phonon thermal conductivity.…”

Section: B Thermal Conductivity and Unified Thermal Resistivity Of Tmentioning

confidence: 75%

“…The reduced thermal conductivity was attributed to the increased scatterings of heat carriers from structural imperfection and the contribution of phonon thermal conductivity. 4,21 Here we will provide an explanation of the abnormal temperature dependent thermal conductivity of these metallic nanostructures.…”

Section: B Thermal Conductivity and Unified Thermal Resistivity Of Tmentioning

confidence: 99%

Temperature dependent behavior of thermal conductivity of sub-5 nm Ir film: Defect-electron scattering quantified by residual thermal resistivity

Cheng

et al. 2015

Journal of Applied Physics

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By studying the temperature-dependent behavior (300 K down to 43 K) of electron thermal conductivity () in a 3.2 nm-thin Ir film, we quantify the extremely confined defect-electron scatterings and isolate the intrinsic phonon-electron scattering that is shared by the bulk Ir. At low temperatures below 50 K,  of the film has almost two orders of magnitude reduction from that of bulk Ir. The film has ∂/∂T>0 while the bulk Ir has ∂/∂T <0. We introduce a unified thermal resistivity (=T/) to interpret these completely different ~T relations. It is found that the film and the bulk Ir share a very similar ~T trend while they have a different residual part (Θ 0 ) at 0 K limit:  0~0 for the bulk Ir, and  0 =5.5 mK 2 /W for the film. The Ir film and the bulk Ir have very close ∂Θ/∂T (75 to 290 K): 6.33×10 -3 mK/W for the film and 7.62×10 -3 mK/W for the bulk Ir. This strongly confirms the similar phonon-electron scattering in them. Therefore, the residual thermal resistivity provides an unprecedented way to quantitatively evaluating defectelectron scattering ( 0 ) in heat conduction. Moreover, the interfacial thermal conductance across the grain boundaries is found larger than that of Al/Cu interface, and its value is proportional to a Corresponding author. Email: xwang3@iastate.edu, Tel: 515-294-2085, Fax: 515-294-3261 2 temperature, largely due to the electron's specific heat. A unified interfacial thermal conductance is also defined and firmly proves this relation. Additionally, the electron reflection coefficient is found to be large (88%) and almost temperature independent.3

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Electrical and thermal transport in single nickel nanowire

Cited by 121 publications

References 23 publications

Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition

Intra-wire coupling in segmented Ni/Cu nanowires deposited by electrodeposition

Thermal and electrical conductivity of approximately 100-nm permalloy, Ni, Co, Al, and Cu films and examination of the Wiedemann-Franz Law

Temperature dependent behavior of thermal conductivity of sub-5 nm Ir film: Defect-electron scattering quantified by residual thermal resistivity

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