## 摘要

We report the results of yttrium substitution on the electrical resistivity (ρ), the thermal conductivity (κ), as well as the Seebeck coefficient (S) of the Sr_{1-x}Y_{x}Al_{2}Si_{2} alloys with 0 ≤ x ≤ 0.20. Both ρ(T) and S(T) data suggest that SrAl _{2}Si_{2} is a semimetallic, low charge carrier density system with a pseudogap at the Fermi level density of states (DOS). Upon substituting Y onto the Sr sites, the electrical resistivity and the absolute value of the Seebeck coefficient decrease significantly. Such an observation can be associated with the modification of the electronic band structure due to electron doping via Y substitution. Analysis of the thermal conductivity reveals the contribution of various thermal scattering mechanisms through chemical substitution. Theoretical studies with density functional theory are also employed to investigate the electronic band structure of Sr_{1-x}Y _{x}Al_{2}Si_{2}. It is revealed that SrAl _{2}Si_{2} possesses a shallow DOS at the Fermi level with both n-type and p-type charge carriers. Upon Y substitution a shift in the Femi level occurs such that the Sr_{1-x}Y_{x}Al_{2}Si_{2} system becomes more metallic with increasing x, being consistent with the experimental findings.

原文 | English |
---|---|

頁（從 - 到） | 1448-1454 |

頁數 | 7 |

期刊 | Intermetallics |

卷 | 19 |

發行號 | 10 |

DOIs | |

出版狀態 | Published - 2011 十月 |

## All Science Journal Classification (ASJC) codes

- 化學 (全部)
- 材料力學
- 機械工業
- 金屬和合金
- 材料化學