Confirmation of Semiconducting Behavior in TaIrGe

Despite being exclusively composed of metallic elements, the half-Heusler compound TaIrGe has been predicted to be a semiconductor with a large indirect gap. Several experimental results, however, have shown metallic behavior. This discrepancy between theoretical prediction and experimental observation is assumed to be due to difficulties in material synthesis. Specifically, the presence of several neighboring phases prevents the synthesis of TaIrGe in single-phase form. With that in mind, we implement focused-ion-beam structuring to polycrystalline TaIrGe. This work does not only provide evidence for intrinsic semiconducting behavior of TaIrGe, but also serves as the first example of selective domain structuring in a polycrystalline material. This novel approach gives a rare opportunity to access materials that cannot be synthesized in single-phase form, sparing costly and time-consuming synthesis efforts, which are frequently futile.