From Insulator to Metal: Chemical Design of Electronic Transitions

Illustration (upper) of the atomic scale chemical ordering in layered oxides that provides structural control over an insulator-to-metal transition as indicated in the series of lower panels: At fixed composition (LaSr)AlO4 can be transformed from a wide-band gap insulator (left) to a metal (right). Broken lines indicate the position of the band edges.
Illustration (upper) of the atomic scale chemical ordering in layered oxides that provides structural control over an insulator-to-metal transition as indicated in the series of lower panels: At fixed composition (LaSr)AlO4 can be transformed from a wide-band gap insulator (left) to a metal (right). Broken lines indicate the position of the band edges.

Scientific Achievement

We identified the relationship between local structural distortions, induced by chemical ordering of cations, and the interactions governing the electronic state (insulator or metal) of LaSrAlO4. The structure of this compound hosts a broad range of chemistries known to exhibit metal-to-insulator (MIT) transitions and will enable future materials design.

Significance and Impact

Our electronic structure calculations on the model system enabled us to formulate a structural descriptor capable of predicting the changes in the electronic gap without having to perform a compute-intensive calculation. This descriptor can be utilized for future high-throughput screening and discovery of digital layered oxides exhibiting MITs, which can be integrated into future logic devices based on current-voltage characteristics.

Additional Materials

Designing Materials to Revolutionize and Engineer our Future (DMREF)