Jia–Ruei Chang , Sinn-wen Chen , He-Cheng Yang , Cheng-Hsi Ho
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引用次数: 0
Abstract
Background
Bi2Te3 is the most frequently used thermoelectric compound, while Co exhibits promise as a barrier layer candidate. To provide fundamental information, the Bi-Co-Te phase equilibria isothermal sections at 500 and 400 ℃, as well as the Co/Bi2Te3 interfacial reactions at 500, 400, and 300 ℃, were determined.
Methods
The Bi-Co-Te alloys and Bi2Te3 substrates were synthesized using high-purity constituent elements. To form the Co/Bi2Te3 couples, Co was electroplated onto the Bi2Te3 substrates, after which they were subjected to reactions at specific temperatures.
Significant findings
In the Bi-Co-Te ternary system, no ternary compounds were found, and all the binary compounds have limited solubility for ternary elements. In the Co/Bi2Te3 couples, significant interfacial reactions were observed. The results suggest that Co alone is not a suitable barrier layer. The reaction paths are Co/CoTe/(Bi2)m(Bi2Te3)n/Bi2Te3 when reacted at 400 and 300 ℃. Although 500 ℃ is below the melting points of both Co and Bi2Te3, surprising liquation occurred, and the reaction path is Co/CoTe/Co+ (Bi2)m(Bi2Te3)n +liquid (I)/Bi2Te3 at 500 ℃. Based on the morphologies and results of the reaction path, it is concluded the dominating diffusion species is Te.
期刊介绍:
Journal of the Taiwan Institute of Chemical Engineers (formerly known as Journal of the Chinese Institute of Chemical Engineers) publishes original works, from fundamental principles to practical applications, in the broad field of chemical engineering with special focus on three aspects: Chemical and Biomolecular Science and Technology, Energy and Environmental Science and Technology, and Materials Science and Technology. Authors should choose for their manuscript an appropriate aspect section and a few related classifications when submitting to the journal online.