我們研究Fe2VGa1+x 化合物之非理想配比效應對於電阻
(ρ)、熱傳導(κ)、熱電勢(S)之影響。經量測Fe2VGa 在室
溫其主要載子為電洞，顯示其為p-type 物質。熱電勢(S)之
值約為30μV/K。當些許的改變Ga 原子比例，使之成為非理
想配比。顯著的熱電勢(S)改變將由正值變為負值。能帶的
計算將伴隨著其他的實驗結果和相關的討論。此外，我們將
討論Fe2VGa1+x 之熱電性質。

We report on the effect of off-stoichiometry on the
temperature dependence of electrical resistivity, thermal
conductivity, as well as thermoelectric power in the
Heusler-type Fe2VGa1+x compounds. Seebeck coefficient (S)
measurements indicate that stoichiometric Fe2VGa is a p-type
material with a moderate S value of about 30 µV/K at room
temperature. For the slightly off-stoichiometric alloys, a
significant enhancement on Seebeck coefficients accompanied
by a sign change is observed. The features are compared with
other experimental results and are related to issues raised by band-structure calculations. The improvement of thermoelectric performance in these compounds will be discussed.

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