Speaker: Man Suk SONG – Weizmann Institute of Science, Israel
The synthesis of advanced materials with controlled composition, structure, and functionality continues to expand the field of materials science. Here, a topotactic mutual-exchange growth method is presented, transforming III-V semiconductor nanowires and thin films into exotic magnetic Zintl compounds via molecular beam epitaxy (MBE). This unique mechanism involves solid-state exchange of Europium (Eu) and Indium (In), forming single-crystalline Zintl phases while preserving the original semiconductor lattice motifs. Wurtzite InAs nanowires are topotactically converted into Eu3In2As4 nanowires, exhibiting antiferromagnetic transitions and classified as C2T axion insulators with chiral hinge modes and Dirac surface states. Zincblende InAs(Sb) nanowires similarly convert to Eu5In2As6, featuring distinct antiferromagnetic phases around 7 K and 16 K, classified as antiferromagnets as well as potential altermagnets for spintronic applications. This growth mechanism has been extended to thin-films and has enabled the exploration of new combinations of Zintl compounds using other III-V semiconductor materials, such as GaAs and InP. Furthermore, this topotactic mutual-exchange approach offers new avenues for designing magnetic, thermoelectric, and topological materials, significantly advancing applications in spintronics, quantum computing, and electronics.
References
[1] [1] Song, M. S., et al. Topotaxial mutual-exchange growth of magnetic Zintl Eu3In2As4 nanowires with axion insulator classification. Nat. Nanotechnol. 19, 1796–1803 (2024).
[2] Song, M. S., et al. Topotactic growth of Zintl phase Eu5In2As6 nanowires with antiferromagnetic behavior. Nano Lett. (2025).
Host: Francesco Rossella