By applying a mechanical force to strain its crystal structure, researchers forced Alpha-tin (gray tin) to behave like 3D graphene and exhibit a novel electronic phase, placing it in the recently discovered class of topological Dirac semimetals.
Gray tin (α-tin), is a non-metal with semiconducting and diamagnetic properties. Being unalterable, gray tin is used to cover steel (tinning). Tinplate, used in the manufacture of tin cans, is obtained by coating steel or wrought iron with molten tin.Gray tin, known as tin pest, could have quantum computing applications.Click To Tweet
Gray tin as 3D Graphene-like Nonmetal
Known since antiquity, tin is rare (comprising 0.003% of the Earth’s crust) yet indispensable to civilization, used in electronics, goldsmithing, and decoration. Now, scientists have discovered a new property of gray tin.
A research team found that gray tin, also known as alpha-tin, exhibits a novel electronic phase when its crystal structure is strained. As such, alpha-tin is now the only simple element included in the 3D materials known as TDSs (topological Dirac semimetals). Until now, this class was comprised of only two other TDS materials, discovered in 2013.
This discovery is the result of research conducted by Professor Tai-Chang and Caizhi Xu, a physics graduate student, at the University of Illinois at Urbana-Champaign, along with researchers from the Advanced Light Source at the Lawrence Berkeley National Laboratory and six other international institutions. An article on the findings was published in Physical Review Letters.
TDSs have electronic properties similar to graphene in 3D. TDSs are composed of different elements, but this new work reveals that the non-metallic form of tin can exhibit properties of TDSs by straining its crystal structure.
Applications of Alpha-tin
These findings show that strain engineering would open up many possibilities, by forcing common materials to exhibit novel properties. The research team is currently experimenting a different way to apply strain on gray tin.
“TDSs are of profound interest to condensed matter physicists,” said Caizhi Xu, “primarily because they exhibit a number of novel physical properties, including ultrahigh carrier mobility, giant linear magnetoresistance, chiral anomaly, and novel quantum oscillations.”
Thanks to its high carrier mobility and magnetoresistance, alpha-tin could be used to develop ultrafast and ultra-compact electronic devices, such as storage devices and hard disks. Additionally, this discovery could be a basis for further research related to optical properties and superconductivity.