اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدImprovement in thermoelectric properties by tailoring at In and Te site in In2Te5
147
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We study role of site substitutions at In and Te site in In2Te5 on the thermoelectric behavior. Single crystals with compositions In2(Te1-xSex)5 (x = 0, 0.05, 0.10) and Fe0.05In1.95(Te0.90Se0.10)5 were prepared using modified Bridgman-Stockbarger technique. Electrical and thermal transport properties of these single crystals were measured in the temperature range 6 - 395 K. A substantial decrease in thermal conductivity is observed in Fe substituted samples attributed to the enhanced phonon point-defect scattering. Marked enhancement in Seebeck coefficient S along with a concomitant suppression of electrical resistivity r{ho} is observed in Se substituted single crystals. An overall enhancement of thermoelectric figure of merit (zT) by a factor of 310 is observed in single crystals of Fe0.05In1.95(Te0.90Se0.10)5 compared to the parent In2Te5 single crystals.
قيم البحث
اقرأ أيضاً
We report a strategy based on introduction of point defects for improving the thermoelectric properties of FeSb2, a promising candidate for low temperature applications. Introduction of Sb deficiency to the tune of 20% leads to enhancement in the val
ues of electrical conductivity ({sigma}) and Seebeck coefficient (S) accompanied with a concomitant suppression in lattice thermal conductivity (k{appa}lat) values in samples prepared using conventional solid state reaction route. These observations in polycrystalline FeSb2-x provides ample motivation for a dedicated exploration of thermoelectric behavior of the corresponding single crystalline as well as hot-pressed polycrystalline counterparts.
We analyze the anisotropic electrical and thermal transport measurements in single crystals of In2Te5 belonging to monoclinic space group C12 c1 with the temperature gradient applied parallel and perpendicular to the crystallographic c-axis of the cr
ystals. The thermal conductivity along the c-axis thermal conductivity parallel was found to smaller by a factor of 2 compared to the thermal conductivity along the direction perpendicular to the c-axis over the entire temperature range. In contrast, the Seebeck coefficient along the c-axis parallel was found to be higher than its value along the direction perpendicular to the c-axis. At room temperature, the figure of merit ZT parallel is found to be 4 times larger as compared to the figure of merit ZT perpendicular.
Lead and tin chalcogenides have been studied widely due to their promising thermoelectric (TE) properties. Further enhancement in their TE efficiency has been reported upon the reduction of the dimension, which is an important feature in modern devic
e fabrications. Using density functional theory combined with the Semi-classical Boltzmann transport theory, we studied the structural, electronic and TE properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Te) monolayers. Spin-orbit coupling was found to have significant effects on their electronic structure, particularly for the heavy compounds. Structural optimization followed by phonon transport studies prevailed that the rectangular ({gamma}-) phase is energetically the most favorable for SnS and SnTe monolayers, whereas the square structure is found the most stable for PbS and PbTe monolayers. Our results are in good agreement with previous studies. These 2D materials exhibit high Seebeck coefficients and power factors along with low lattice thermal conductivities, which are essential features of good TE materials. The maximum figure of merits (ZT) of 1.04, 1.46, 1.51 and 1.94 are predicted for n-type SnS, SnTe, PBS and p-type PbTe monolayers respectively at 700 K, which are higher than their bulk ZT values. Hence, these monolayers are promising candidates for TE applications.
Ni$_{50}$Mn$_{34}$In$_{16}$ undergoes a martensitic transformation around 250 K and exhibits a field induced reverse martensitic transformation and substantial magnetocaloric effects. We substitute small amounts Ga for In, which are isoelectronic, to
carry these technically important properties to close to room temperature by shifting the martensitic transformation temperature.
Thermoelectric materials are opening a promising pathway to address energy conversion issues governed by a competition between thermal and electronic transport. Improving the efficiency is a difficult task, a challenge that requires new strategies to
unearth optimized compounds. We present a theory of thermoelectric transport in electron doped SrTiO3, based on a realistic tight binding model that includes relevant scattering processes. We compare our calculations against a wide panel of experimental data, both bulk and thin films. We find a qualitative and quantitative agreement over both a wide range of temperatures and carrier concentrations, from light to heavily doped. Moreover, the results appear insensitive to the nature of the dopant La, B, Gd and Nb. Thus, the quantitative success found in the case of SrTiO3, reveals an efficient procedure to explore new routes to improve the thermoelectric properties in oxides.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
