Department: University of Delaware. Department of Materials Science and Engineering.
Publisher: American Association for the Advancement of Science (AAAS)
Date Issued: 2015-11-06
Abstract: Resistances that exceed the Mott-Ioffe-Regel limit (known as bad metal behavior) and non-Fermi liquid behavior are
ubiquitous features of the normal state of many strongly correlated materials. We establish the conditions that lead
to bad metal and non-Fermi liquid phases in NdNiO3, which exhibits a prototype bandwidth-controlled metalinsulator
transition. We show that resistance saturation is determined by the magnitude of Ni eg orbital splitting,
which can be tuned by strain in epitaxial films, causing the appearance of bad metal behavior under certain
conditions. The results shed light on the nature of a crossover to a non-Fermi liquid metal phase and provide
a predictive criterion for Anderson localization. They elucidate a seemingly complex phase behavior as a function
of film strain and confinement and provide guidelines for orbital engineering and novel devices.
E. Mikheev, A. J. Hauser, B. Himmetoglu, N. E. Moreno, A. Janotti, C. G. Van de Walle, S. Stemmer, Tuning bad metal and non-Fermi liquid behavior in a Mott material: Rare-earth nickelate thin films. Sci. Adv. 1, e1500797 (2015).