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Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Thermoelectric properties of Ca0.8Dy0.2MnO3 synthesized by solution combustion process | Park and Lee Nanoscale Research Letters 2011 6 548 http www.nanoscalereslett.eom content 6 1 548 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Thermoelectric properties of Ca0.8Dy0.2MnO3 synthesized by solution combustion process Kyeongsoon Park and Ga Won Lee Abstract High-quality Ca0.8Dy0.2MnO3 nano-powders were synthesized by the solution combustion process. The size of the synthesized Ca0.8Dy0.2MnO3 powders was approximately 23 nm. The green pellets were sintered at 1150-1300 C at a step size of 50 C. Sintered Ca08Dy02MnO3 bodies crystallized in the perovskite structure with an orthorhombic symmetry. The sintering temperature did not affect the Seebeck coefficient but significantly affected the electrical conductivity. The electrical conductivity of Ca0.8Dy0.2MnO3 increased with increasing temperature indicating a semiconducting behavior. The absolute value of the Seebeck coefficient gradually increased with an increase in temperature. The highest power factor 3.7 X 10-5 Wm-1 K-2 at 800 C was obtained for Ca0.8Dy0.2MnO3 sintered at 1 250 C. In this study we investigated the microstructure and thermoelectric properties of Ca0.8Dy0.2MnO3 depending on sintering temperature. Keywords electrical conductivity solution combustion process Seebeck coefficient power factor Ca0.8Dy0.2MnO3 1. Introduction Solid-state thermoelectric power generation based on Seebeck effects has potential applications in waste-heat recovery. Thermoelectric generation is thermodynamically similar to conventional vapor power generation or heat pumping cycles 1 . Thermoelectric devices are not complicate have no moving parts and use electrons as working fluid instead of physical gases or liquids 1 2 . The efficiency of thermoelectric devices is determined by the materials dimensionless figure-of-merit defined as ZT ơa K T where Ơ a K and T are the electrical conductivity Seebeck coefficient thermal conductivity and absolute temperature respectively. To be a good .
