Published 07/15/2025 at 592 × 426 in Fabrication of a Pb-Sn nanowire array gas sensor using a novel high vacuum die casting technique Fig. 3. Cross-section SEM image of the Pb-Sn alloy nanowires in a high-density array structure Fig. 3. Cross-section SEM image of the Pb-Sn alloy nanowires in a high-density array structure