اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدPhenomenological analysis of transverse thermoelectric generation and cooling performance in magnetic/thermoelectric hybrid systems
157
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We phenomenologically calculate the performance of the recently-observed Seebeck-driven transverse thermoelectric generation (STTG) for various systems in terms of the thermopower, power factor, and figure of merit to demonstrate the usefulness of STTG. The STTG system consists of a closed circuit comprising thermoelectric and magnetic materials which exhibit the Seebeck and anomalous Hall effects, respectively. When a temperature gradient is applied to the hybrid system, the Seebeck effect in the thermoelectric material layer generates a longitudinal charge current in the closed circuit and the charge current subsequently drives the anomalous Hall effect in the magnetic material layer. The anomalous Hall voltage driven by the Seebeck effect has a similar symmetry to the transverse thermoelectric conversion based on the anomalous Nernst effect. We find that the thermoelectric properties of STTG can be much better than those of the anomalous Nernst effect by increasing the Seebeck coefficient and anomalous Hall angle of the thermoelectric and magnetic materials, respectively, as well as by optimizing their dimensions. We also formulate the electronic cooling performance in the STTG system, confirming the reciprocal relation for the hybrid transverse thermoelectric conversion.
قيم البحث
اقرأ أيضاً
The transverse thermoelectric effect refers to the conversion of a temperature gradient into a transverse charge current, or vice versa, which appears in a conductor under a magnetic field or in a magnetic material with spontaneous magnetization. Amo
ng such phenomena, the anomalous Nernst effect in magnetic materials has been receiving increased attention from the viewpoints of fundamental physics and thermoelectric applications owing to the rapid development of spin caloritronics and topological materials science. In this research trend, a conceptually different transverse thermoelectric conversion phenomenon appearing in thermoelectric/magnetic hybrid materials has been demonstrated, enabling the generation of a large transverse thermopower. Here, we review the recent progress in fundamental and applied studies on the transverse thermoelectric generation using magnetic materials. We anticipate that this perspective will further stimulate research activities on the transverse thermoelectric generation and lead to the development of next-generation thermal energy harvesting and heat-flux sensing technologies.
Transverse thermoelectric effects in response to an out-of-plane heat current have been studied in an external magnetic field for ferromagnetic superlattices consisting of La0.67Sr0.33MnO3 and SrRuO3 layers. The superlattices were fabricated on SrTiO
3 substrates by pulsed laser deposition. We found that the sign of the transverse thermoelectric voltage for the superlattices is opposite to that for La0.67Sr0.33MnO3 and SrRuO3 single layers at 200 K, implying an important role of spin Seebeck effects inside the superlattices. At 10 K, the magnetothermoelectric curves shift from the zero field due to an antiferromagnetic coupling between layers in the superlattices.
Whether porosity can effectively improve thermoelectric performance is still an open question. Herein we report that thermoelectric performance can be significantly enhanced by creating porosity in n-type Mg3.225Mn0.025Sb1.5Bi0.49Te0.01, with a ZT of
~0.9 at 323 K and ~1.6 at 723 K, making the average ZT much higher for better performance. The large improvement at room temperature is significant considering that such a ZT value is comparable to the best ZT at this temperature in n-type Bi2Te3. The enhancement was mainly from the improved electrical mobility and multi-scale phonon scattering, particularly from the well-dispersed bismuth nano-precipitates in the porous structure. We further extend this approach to other thermoelectric materials such as half-Heuslers Nb0.56V0.24Ti0.2FeSb and Hf0.25Zr0.75NiSn0.99Sb0.01 and Bi0.5Sb1.5Te3 showing similar improvements, further advancing thermoelectric materials for applications.
Using first-principles method and Boltzmann theory, we provide an accurate prediction of the electronic band structure and thermoelectric transport properties of alpha-MgAgSb. Our calculations demonstrate that only when an appropriate exchange-correl
ation functional is chosen can we correctly reproduce the semiconducting nature of this compound. By fine tuning the carrier concentration, the thermoelectric performance of alpha-MgAgSb can be significantly optimized, which exhibits a strong temperature dependence and gives a maximum ZT value of 1.7 at 550 K.
Tin chalcogenides (SnS, SnSe, and SnTe) are found to have improved thermoelectric properties upon the reduction of their dimensionality. Here we found the tilted AA + s stacked two-dimensional (2D) SnTe bilayer as the most stable phase among several
stackings as predicted by the structural optimization and phonon transport properties. The carrier mobility and relaxation time are evaluated using the deformation potential theory, which is found to be relatively high due to the high 2D elastic modulus, low deformation potential constant, and moderate effective masses. The SnTe bilayer shows a high Seebeck coefficient, high electrical conductivity, and ultralow lattice thermal conductivity. High TE figure of merit (ZT) values, as high as 4.61 along the zigzag direction, are predicted for the SnTe bilayer. These ZT values are much enhanced as compared to the bulk as well as monolayer SnTe and other 2D compounds.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
