Franckeite is a naturally occuring exfolitable crystal which is found to be a topological insulator.
Recent papers
Exfoliation of natural van der Waals heterostructures to a single unit cell thickness. Natural communciations 2017
Franckeite as an Exfoliable Naturally Occurring Topological Insulator. Nano Letters. 2021
Franckeite (Pb5Sn3Sb2S14) crystal
£399.00Price