Matching Items (2)
Description
In a pure spin current, electrons of opposite spins flow in opposite directions, thus information is conveyed by spin current without any charge current. This process almost causes no power consumption, which has the potential to realize ultra-low-power-consumption electronics. Recently, thermal effects in magnetic materials have attracted a great deal of attention because of its potential to generate pure spin currents using a thermal gradient (∇T), such as the spin Seebeck effect. However, unlike electric potential, the exact thermal gradient direction is experimentally difficult to control, which has already caused misinterpretation of the thermal effects in Py and Py/Pt films. In this work, we show that a well-defined ∇T can be created by two thermoelectric coolers (TECs) based on Peltier effect. The ∇T as well as its sign can be accurately controlled by the driven voltage on the TECs. Using a square-wave driven potential, thermal effects of a few μV can be measured. Using this technique, we have measured the anomalous Nernst effect in magnetic Co/Py and Py/Pt layers and determined their angular dependence. The angular dependence shows the same symmetry as the anomalous Hall effect in these films.
This work has been carried out under the guidance of the author’s thesis advisor, Professor Tingyong Chen.
This work has been carried out under the guidance of the author’s thesis advisor, Professor Tingyong Chen.
ContributorsSimaie, Salar (Author) / Chen, Tingyon (Thesis director) / Alizadeh, Iman (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / Department of Physics (Contributor)
Created2015-05
Description
The energy consumed by buildings occupies a large part of energy consumption and carbon emissions. Meanwhile, enormous amounts of waste heat from buildings and the swiftly increasing demand for electric energy have become one of the essential contradictions that scientists pay attention to. As a result, how to make use of the waste heat to generate electric energy becomes an appreciable research topic. In the latest research, it is common to convert the thermal energy generated by the temperature difference into electrical energy using the Seebeck effect. In previous research, a prototype of a thermogalvanic cell with graphite as the electrodes and a combination of Iron (II) and Iron (III) perchlorate salts (Fe(ClO4)2, Fe(ClO4)3) as the electrolyte, and with a 3D-printed Schwarz-P structure, was designed and assembled for achieving the energy conversion. The research shows that the incorporation of a 3D-printed Schwarz-P structure improves the thermogalvanic cell’s performance and increases the temperature difference across the cell. Here we focus on the same type of thermogalvanic cell prototype and keep the same working temperature difference but use different electrolyte concentrations (0.05, 0.10, 0.15, 0.20, and 0.25 mol/L) to measure the electric output, including open-circuit voltage, short-circuit current, and maximum output power, and the internal resistance. The results indicate that the open-circuit voltage and maximum output power increase with the rise of electrolyte concentrations, and the short-circuit current decreases with the rise of electrolyte concentrations.
ContributorsHan, Xiaochuan (Author) / Phelan, Patric (Thesis advisor) / Huang, Huei-Ping (Committee member) / Bocanegra, Luis (Committee member) / Arizona State University (Publisher)
Created2022