Effect of Europium Substitution on Thermoelectric Properties of Noble-Metal Silicon Clathrates with Ba8−xEuxCuySi46−y Nominal Compositions
| Autor: | K. Koga, S. Harima, Kouji Akai, K. Okita, Hiroaki Anno, Masahiro Hokazono, Takahiro Nakabayashi |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Electron mobility
Materials science Mechanical Engineering Analytical chemistry Ab initio Mineralogy chemistry.chemical_element Electronic structure Condensed Matter Physics Effective mass (solid-state physics) chemistry Mechanics of Materials Electrical resistivity and conductivity Seebeck coefficient Thermoelectric effect General Materials Science Europium |
| Zdroj: | MATERIALS TRANSACTIONS. 53:1220-1225 |
| ISSN: | 1347-5320 1345-9678 |
| DOI: | 10.2320/matertrans.e-m2012816 |
| Popis: | The effect of the substitution of a rare-earth element for a guest element on the electronic and thermoelectric properties is investigated for clathrates with the nominal composition Ba81xEuxCuySi461y (x = 0, 1, 2; y = 4, 5, 6). The Seebeck coefficient and the electrical conductivity of the rare-earth-substituted Ba81xEuxCuySi461y samples are consistent with n-type conduction and metal-like behavior. The Hall carrier mobility of Ba81xEuxCu6Si40 at room temperature decreases with increasing Eu substitution. The conduction band effective mass of rare-earth-substituted Ba81xEuxCu6Si40 (x = 1, 2) is experimentally estimated to be larger than that of Ba8Cu6Si40. On the basis of ab initio electronic structure calculations for Ba6Eu2Cu6Si40 and Ba8Cu6Si40, it is deduced that the conduction band edges of Ba8Cu6Si40 are modified by the substitution of Eu for the guest atom Ba, resulting in an increase in the density-of-states effective mass, which is consistent with the experimental result. [doi:10.2320/matertrans.E-M2012816] |
| Databáze: | OpenAIRE |
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