Thermomechanical Nanomolding of Topological Materials

Topological nanomaterials have novel symmetry-protected electronic states that are advantageous for applications such as microelectronics and quantum computing. Fabrication of topological nanomaterials is hindered by the lack of high throughput synthesis methods that enable tight control of phase and morphology. Here, we present the use of thermomechanical nanomolding (TMNM) to fabricate nanowires of topological materials. TMNM is a materials agnostic, scalable fabrication process where a bulk feedstock is pressed through a nanoporous mold at elevated temperatures and pressures to form defect-free, single crystal nanowires.



We used TMNM to fabricate nanowires from topological triple-point metal MoP and CoSn. Due to their symmetry-protected surface states, these materials have enhanced electronic properties that make them attractive candidates for next-generation interconnects. High-resolution S/TEM analysis reveals formation of single-crystal nanowires with uniform composition along the wire length. Surprisingly, we find that metastable Mo₄P₃ is formed from the MoP feedstock, demonstrating that elevated temperatures, pressures, and interfacial effects in TMNM can provide a novel route to access metastable states. Four probe measurements show low resistivity values for both Mo₄P₃ and CoSn. Thus, we present TMNM as a high throughput fabrication method to form nanowires of topological materials with controlled structure and potential for applications in computing technologies.