Journal article

Publication year: 2008

Pages: 391-398

Journal: Nature Materials

Volume number: 7

ISSN: 1476-1122

eISSN: 1476-4660

DOI Link: https://doi.org/10.1038/nmat2164

Publisher: Nature Research

Abstract: 
Insulator - metal transitions are well known in transition-metal oxides, but inducing an insulator - metal transition in the oxide of a main group element is a major challenge. Here, we report the observation of an insulator - metal transition, with a conductivity jump of seven orders of magnitude, in highly non-stoichiometric, amorphous gallium oxide of approximate composition GaO1.2 at a temperature around 670 K. We demonstrate through experimental studies and density-functional-theory calculations that the conductivity jump takes place at a critical gallium concentration and is induced by crystallization of stoichiometric Ga2O3 within the metastable oxide matrix - in chemical terms by a disproportionation. This novel mechanism - an insulator - metal transition driven by a heterogeneous solid-state reaction - opens up a new route to achieve metallic behaviour in oxides that are expected to exist only as classic insulators.

Harvard Citation style: Nagarajan, L., De Souza, R., Samuelis, D., Valov, I., Börger, A., Janek, J., et al. (2008) A chemically driven insulator-metal transition in non-stoichiometric and amorphous gallium oxide, Nature Materials, 7, pp. 391-398. https://doi.org/10.1038/nmat2164

APA Citation style: Nagarajan, L., De Souza, R., Samuelis, D., Valov, I., Börger, A., Janek, J., Becker, K., Schmidt, P., & Martin, M. (2008). A chemically driven insulator-metal transition in non-stoichiometric and amorphous gallium oxide. Nature Materials. 7, 391-398. https://doi.org/10.1038/nmat2164