Effect of growth temperature on the terahertz-frequency conductivity of the epitaxial transparent conducting spinel NiCo2O4 films
Chia, Elbert E. M.
Kim, Dae Ho
Date of Issue2013
School of Physical and Mathematical Sciences
We have measured the terahertz-frequency optical conductivity of the epitaxial inverse spinel NiCo2O4 films grown at different temperatures. The low-temperature-grown film exhibits a metallic behavior with ferrimagnetic ordering, while the high-temperature-grown film shows greatly suppressed magnetization and insulating behavior. Both films exhibit band-like coherent conduction at intermediate temperatures, albeit with very different carrier densities consistent with the proposed models of cation valencies in this mixed-valence material. Both films also display a crossover to incoherent transport at low temperatures, indicating a disorder-induced tendency toward localization.
© 2013 The Authors. This paper was published in AIP Advances and is made available as an electronic reprint (preprint) with permission of the authors. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.4821548]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.