The spin seebeck effect observed here is directly applicable to the production of spinvoltage generators, which are crucial for driving spintronic15,16,17,18 devices. Nano idea openaccess spinpolarizedtransportandspin. Quantitative temperature dependence of longitudinal spin. Observation of the spinseebeck effect in a ferromagnetic. Seebeck effect synonyms, seebeck effect pronunciation, seebeck effect translation, english dictionary definition of seebeck effect. Seebeck effect definition of seebeck effect by the free. Electric voltage spin voltage electric current flows. This physics is the basis for thermoelectric sensors and coolers. Sep 28, 2012 the spin seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters. Goennenwein2,4, arunava gupta5, maximilian schmid6, christian h.
The spin seebeck effect is a spinmotive force generated by a temperature gradient in a ferromagnet that can be detected via normal metal contacts through the inverse spin hall effect k. The direction and the intensity of the gradient allow to excite the spin wave modes of each layer selectively. Robust spin current generated by the spin seebeck effect. The inverse spin hall effect converts the injected spin current into a transverse charge voltage, thereby. Enhanced spin seebeck effect signal due to spin momentum locked topological surface states zilong jiang, 1 cuizu chang, 2 massoud ramezani masir, 3 chi tang, 1 yadong xu, 1 jagadeesh s. The observed behavior cannot be explained as an interface effect or by variations of the material parameters. Spinseebeck effect dongwook go department of physics, postech 2. The longitudinal spin seebeck effect sse, a pure spin current effect driven by a vertical heat current, was established in the bilayer structures consisting of a magnetic insulator such as yttrium iron garnet and a heavy metal such as au with strong spin orbit coupling soc but a negligible magnetic proximity effect 1, 2. Kenichi uchida of tohoku university keio university at that time.
The creation of an electrical potential across points in a metal that are at different temperatures, caused by the tendency of valence electrons in the. Picosecond spin seebeck effect university of illinois at. Modern scientists have been able to provide another dimension to the study of seebeck effect by studying the effect of application of heat supply to magnetized electrical conductors. There are three major effects involved in a thermocouple circuit. The charge carriers, driven by the thermal gradient, reposition themselves in accordance to their individual spin or angular momentum. Combining nernst and sse in bulk materials would enable devices with.
Jul 28, 2016 scientists unveil fundamental properties of spin seebeck effect by universitaet mainz thermally excited spin waves carry a spin current from the ferromagnet yig in this case into the metal layer. Thermopower, or historically the seebeck effect, consists of the generation of an electric field, e, in the presence of a temperature gradient. For a given thermal gradient, the electrons in the material separate themselves and generate an electric gradient, in accord with math\delta v s \delta t math where mathsmath is the seebec. The spin seebeck effect sse describes the phenomenon that spin currents can be thermally excited by a temperature gradient across magnetic materials. The seebeck effect the longitudinal thermopower and the inplane nernst effect the transverse thermopower under inplane h were measured on compressive ga,mnas. When the yig magnetization is in the direction, spinmomentum locking in the ti surface states then leads to a net rate of momentum transfer. The ones marked may be different from the article in the profile. For the case of large interdot spin polarization, such as p 0. The spin seebeck effect sse is a novel, only rudimentarily understood effect, which allows for the conversion of a heat flux into electrical energy. History of the seebeck effect discovered by thomas johann seebeck in 1821.
This electric potential can be measured across the hot and the cold ends of the junction. Observation of the spin seebeck effect request pdf researchgate. The spin seebeck effect sse describes the phenomenon that spin currents can be thermally excited by a temperature gradient across a magnetic material. A simple explanation of seebeck effect with its applications. The inverse spin hall effect converts the injected spin current into a transverse charge voltage, thereby producing. Of particular interest is the spin seebeck effect sse that generates pure spin current without the accompany of the charge counterpart, or spin bias characterized by the splitting of spinup and spindown chemical potentials. This cited by count includes citations to the following articles in scholar. Variable temperature seebeck measurement systems mmr technologies, inc. Seebeck effect and seebeck coefficient electrical4u. The spin seebeck e ect attracted a lot of attention due to possible applications. In the seebeck effect, the same phenomena occurs, and there is a generation of electrical potential due to the application of a heat source. It is regarded as a combination of spintronics and thermoelectricity. University of groningen magnon spintronics in noncollinear. Our results reveal a characteristic increase of the longitudinal spin seebeck effect amplitude with the thickness of the insulating ferrimagnetic yig, which levels off at a critical thickness that increases with decreasing temperature.
Both effects showed strong dependence on the direction of h, reflecting inplane magnetization reversal process. This effect has stimulated a strong interest in thermal aspects of spin transport5. In the paramagnet, the spin current is converted into an electric field due to the invserse spin hall effect. The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa via a thermocouple. T s is the thermopower coefficient, in a conductor under the condition of zero net current. Research news new spin seebeck thermoelectric device. Longitudinal spin seebeck effect contribution in transverse. Seebeck e ect is the spin analogy to the conventional seebeck e ect. Recent increases in energy costs here in the united states, industrial growth throughout the world, plus the.
For positivep,theinterdottunnelingratetc, tc,v andthe spinup. He accidentally found that a voltage existed between two ends of a metal bar when a temperature gradient existed within the bar. One such combination of copper constantan, has a seebeck coefficient of 41 microvolt per kelvin at room temperature. Here we demonstrate this property using the spin seebeck effect sse, that is, measuring the transverse thermoelectric response to a temperature gradient. Seebeck effect using a thermocouple and an instrumentation amplifier. The voltage produced between the two points on a conductor when a consistent temperature difference of 1 o kelvin is maintained between them is termed as seebeck coefficient. Longitudinal spin seebeck effect contribution in transverse spin seebeck effect experiments in ptyig and ptnfo daniel meier1, daniel reinhardt1, michael van straaten1, christoph klewe1, matthias althammer2, michael schreier2,3, sebastian t.
Enhanced spin seebeck effect signal due to spinmomentum. Here we demonstrate this property using the spin seebeck effect sse, that is, measuring the transverse thermoelectric response to a temperature gradient across a thin film of yttrium iron garnet. Intrinsic spin seebeck effect in au yig uci physics and. It describes the generation of an electromotive force in a paramagnetic metal, attached to a ferromagnet, by a temperature gradient 9,106.
The product of spinmixing conductance and the interfacial spin seebeck coefficient determined is of the order of 108 a m2 k1. Spin seebeck effect and thermoelectric phenomena in. The spin seebeck effect is not only observed in ferromagnetic metal, but also in ferromagnetic semiconductor and. In this article we propose a simple and lowcost experimental setup through which science educators can demonstrate the seebeck effect using a thermocouple and an instrumentation amplifier. The seebeck and peltier effects are different manifestations of the same physical process. Spin seebeck effect quantum dots spindependent interdot coupling. Figure 1 the charge seebeck effect is a redistribution of charge due to an applied temperature gradient. Using micromagnetic simulations, we have investigated spin dynamics in a spinvalve bilayer in the presence of a thermal gradient. The spin seebeck effect refers to the generation of a spin voltage caused by a. The seebeck effect is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a. Indications of the origin of the spin seebeck effect discovered. It describes the generation of an electromotive force in a paramagnetic metal, attached to a.
Discovered in 1834 an electrical current creates a cooling or heating effect at the junction depending on the direction of current flow. Conversely, when a voltage is applied to it, heat is transferred from one side to the other, creating a temperature difference. Spinpolarized transport and spin seebeck effect in triple. Peltier effect jean charles athanase peltier 17851845 peltier effect. The spin seebeck effect refers to the generation of a spin voltage caused by a temperature gradient in a ferromagnet, which enables the thermal injection of spin currents from the ferromagnet into an attached nonmagnetic metal over a macroscopic scale of several millimeters. Thermoelectric effect, materials, measurement and application energy conservation, use and efficiency are increasing important issues in the daily lives of all people in the modern world. These spin currents can be injected into an adjacent heavy metal layer with a high spin orbit coupling, which allows one to electrically detect the.
Sse from magnontopological surface states interaction. Length scale of the spin seebeck effect andreas kehlberger,1, ulrike ritzmann,2 denise hinzke,2 erjia guo,1 joel cramer,1 gerhard jakob,1 mehmet c. A comment on this article appears in spin seebeck effect. Finally it is possible, to combine time resolved measurements, reported in ch. When two wires composed of dissimilar metals are joined at both ends and one of the ends is heated, there is a continuous current which flows in the thermoelectric circuit. Schematic representation of the spin seebeck effect in different. Scientists unveil fundamental properties of spin seebeck effect. We theoretically consider the spin seebeck effect, the charge seebeck coefficient, and the thermoelectric figure of merit in superconducting. Peltier effect in 1834, a french watchmaker and part time physicist, jean peltier found that an electrical current would produce a temperature gradient at the junction of two dissimilar metals. The spin seebeck effect sse is an emergent thermoelectric phenomenon, which enables a thermaltoelectrical energy conversion via the thermal injection of spin currents from a ferromagnet fm.
Ppt seebeck effect powerpoint presentation free to. This permits to synchronize the magnetization precession of the two layers and to rectify the flows of energy and magnetization through the system. The seebeck effect the seebeck effect, or thermoelectric effect direct conversion of temperature differences into electricity discovered in 1821 by thomas johann. Enhanced spin seebeck effect signal due to spinmomentum locked topological surface states zilong jiang1, cuizu chang2, massoud ramezani masir3, chi tang1, yadong xu1, jagadeesh s. Indications of the origin of the spin seebeck effect. The experiment can be set up and conducted during a 1hour laboratory session. Seebeck effect definition is the thermoelectromotive force generated in a circuit composed of different metals in successive contact when the junctions are not all at the same temperature. The seebeck effect the seebeck effect, or thermoelectric effect direct conversion of temperature differences into electricity discovered in 1821 by thomas johann seebeck found that a voltage existed between two ends of a metal bar.
The spin seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators. Time resolved spin seebeck effect experiments as a probe of. Ab we report timeresolved magnetooptic kerr effect measurements of the longitudinal spin seebeck effect in normal metaly3fe5o12 bilayers driven by an interfacial temperature difference between electrons and magnons. Request pdf observation of the spin seebeck effect the generation of electric voltage by placing a conductor in a temperature gradient is. Recent studies on the spin seebeck effect have been. University of groningen thermoelectric effects in magnetic.
Scientists unveil fundamental properties of spin seebeck. From a fundamental standpoint, the spinseebeck effect, like the chargeseebeck effect, allows insight into the electronic structure of materials. T h t c temperature difference between hot and cold junctions. However, the definition of such a spin current is not straightfor ward, since the. The spinseebeck effect sse 11,12,14 is a practical way to generate such a powerful spinwave current. Theory of magnondriven spin seebeck effect internet archive. The spinseebeck effect in a ferromagnetic semiconductor. Seebeck measurement system thermoelectric measurements the seebeck measurement system. Indications of the origin of spin seebeck effect discovered.
For the case of weak interdot coupling, the three peaks merge into a. From a fundamental standpoint, the spin seebeck effect, like the charge seebeck effect, allows insight into the electronic structure of materials. These spin currents can be injected into an adjacent heavy metal hm layer with a high spinorbit coupling, which allows one to electrically detect the spin currents due to the. Ppt seebeck effect powerpoint presentation free to view. Chien1, 1department of physics and astronomy, johns hopkins university, baltimore, maryland 21218, usa 2department of physics, national tsing hua university, hsinchu 300, taiwan 3department of physics and astronomy, university of california, irvine, california 92697, usa. Sep 07, 2015 the spin seebeck effect sse is a novel, only rudimentarily understood effect, which allows for the conversion of a heat flux into electrical energy, even in electrically nonconducting materials. The seebeck effect is a phenomenon in which a temperature difference between two dissimilar electrical conductors or semiconductors produces a voltage difference between the two substances. Seebeck effect definition of seebeck effect by merriam.
Aug 27, 2017 the seebeck effect might seem to be a paradox. Thermoelectric effect, materials, measurement and application. When a magnon is created or annihilated, an electron flips from majority to minority spinorientation or vice versa to conserve total spin, as illustrated schematically in fig. The seebeck effect a temperature difference causes diffusion of electrons from the hot side to the cold side of a conductor. Of particular interest is the spin seebeck effect sse that generates pure spin current without the accompany of the charge counterpart, or spin bias characterized by the splitting of spin up and spin down chemical potentials. This is a phenomenon in which a temperature gradient applied in a magnetic material produces a spin current along the temperature gradient.
Spin seebeck mechanical force nature communications. Pdf theory of magnondriven spin seebeck effect ken. The seebeck effect describes the voltage or electromotive force emf induced by the temperature difference gradient along the wire. Development in spin seebeck devices maekawa goup jaea, saitoh group tohoku university. The product of spin mixing conductance and the interfacial spin seebeck coefficient determined is of the order of 108 a m2 k1. Thermoelectric devices create a voltage when there is a different temperature on each side.
Combining our measurements with modeling, we show that dipolar. Chien1, 1department of physics and astronomy, johns hopkins university, baltimore, maryland 21218, usa. The spin seebeck effect observed here is directly applicable to the production of spin voltage generators, which are crucial for driving spintronic15,16,17,18 devices. The spin seebeck effect is a spin motive force generated by a temperature gradient in a ferromagnet that can be detected via normal metal contacts through the inverse spin hall effect k. Scientists unveil fundamental properties of spin seebeck effect by universitaet mainz thermally excited spin waves carry a spin current from the.