7 December 2015

When materials get thin

This week at the lab, scientists are using a brand new tool to tweak the crystal structure of materials in the hopes of imbuing them with potentially useful properties.

Using a technique called pulsed laser deposition, physicist Christianne Beekman is creating thin films of materials less than 100 nanometers thick — one one-thousandth the thickness of a sheet of paper. The process involves vaporizing a target material with a class 4 laser, generating a colorful plume of plasma. When that plasma settles on a waiting piece of substrate, the result is a thin film that alters the original structure of the material in a way that can induce new magnetic or electrical properties.

“Sometimes in these complex materials a slight change in the interatomic distance could tip it over to an entirely different phase,” said Beekman. The original “bulk” material might, for example, change from a metal to an insulator in its thin film form (or vice versa) – a nifty trick with potentially powerful applications in electronics and computers. Beekman is also looking at materials that might make excellent solar cells, if photons hitting thin-film versions of them turn out to generate more than one electron per photon.

After creating thin films in this new instrument, Beekman and her team will use MagLab magnets and other facilities to investigate their properties.

“The ability to grow high-quality complex oxide thin films allows us to accelerate materials discovery,” said Beekman, “which will lead to the technologies of tomorrow.”

Video by Stephen Bilenky / Text by Kristen Coyne

Last modified on 10 December 2015