講演情報
[16p-WL2_401-10]Details Matter: Unveiling Role of Sb Stoichiometry in Quaternary half-Heusler Thermoelectrics
〇(PC)Andrei Novitskii1, Illia Serhiienko2, Takao Mori1,3 (1.NIMS, 2.TU Wien, 3.Tsukuba Univ.)
キーワード：
half-Heusler alloys
We identify intrinsic Sb vacancies as the key factor controlling electronic transport in X(Fe0.5Ni0.5)Sb (X = Ti, Zr, Hf). A semiconducting ground state is realized at an effective six valence electrons per atom, consistent with the generalized Slater–Pauling rule. Sb vacancies form naturally during synthesis and annealing, even in nominally stoichiometric samples, shifting the Fermi level from the conduction to the valence band and driving a transition from n- to p-type conduction. Ti- and Zr-based compounds show intrinsic n-type behavior when Sb vacancies are controllably minimized, whereas Hf(Fe0.5Ni0.5)Sb is intrinsically p-type due to unavoidable Sb deficiency. In Ti(Fe0.5Ni0.5)Sb, the conduction type can be reversibly tuned via annealing. These results emphasize intrinsic defect control as a design principle for half-Heusler thermoelectrics.
This work was supported by JST Mirai JPMJMI19A1.
This work was supported by JST Mirai JPMJMI19A1.