A half-metallic full-Heusler Mn₂VAl alloy is a potential p-type thermoelectric material that can directly generate electricity from waste heat via the Seebeck effect. For practical use, the Seebeck coefficient S of Mn₂VAl should be increased while maintaining a high electrical conductivity σ from its half-metallic character. Herein, we achieved this objective through antisite defect engineering. Theoretically, it was predicted that the S was maximized by regulating partial density of states of majority-spin sp-electrons through the control of the fraction of antisite defect, f_AD, between V and Al atoms in Mn₂VAl. Experimentally, a significant increase in S and a slight decrease in σ were observed for an Mn₂VAl sample with an optimal f_AD = 33 %, enhancing the thermoelectric power factor PF by 2.7 times from an Mn₂VAl sample with f_AD = 14 %. Furthermore, we combined the antisite defect engineering with a partial substitution method. An Mn₂V(Al_0.96Si_0.04) sample with f_AD = 33 % exhibited the highest PF = 4.5×10⁻⁴ W m⁻¹ K⁻² at 767 K among the samples. The maximum dimensionless figure-of-merit zT of the Mn₂V(Al_0.96Si_0.04) sample with f_AD = 33 % was measured to be 3.4×10⁻² at 767 K, which is the highest among the p-type half-metallic full-Heusler alloys.

半金属全Heusler Mn ₂ VAl合金是一种潜在的p型热电材料，可以通过塞贝克效应直接利用废热发电。在实际应用中，应提高Mn ₂ VAl的塞贝克系数S，同时保持其半金属特性的高电导率σ。在这里，我们通过反现场缺陷工程实现了这一目标。理论上，预测通过控制 Mn < 中 V 和 Al 原子之间的反位缺陷分数 f _AD 来调节多数自旋 sp 电子态的部分密度，从而使 S 最大化。 b3> VA1。实验中，观察到最佳 f _AD = 33 % 的 Mn ₂ VAl 样品的 S 显着增加，而 σ 略有下降，热电功率因数 PF 提高了 2.7 f _AD = 14 % 的 Mn ₂ VAl 样品的倍数。此外，我们将反位点缺陷工程与部分替换方法相结合。 f _AD = 33 % 的 Mn ₂ V(Al _0.96 Si _0.04 ) 样品表现出最高的 PF = 4.5×10 <样品中 b12> W m ⁻¹ K ⁻² 在 767 K 处。 f _AD = 33 时 Mn ₂ V(Al _0.96 Si _0.04 ) 样品的最大无量纲品质因数 zT 767 K 时测得 % 为 3.4×10 ⁻² ，这是 p 型半金属全霍斯勒合金中最高的。