Abstract
We have measured optical reflectivity of Li- and Ti-doped NiO (LTNO) in the infrared range at various temperatures. A Drude-type absorption is found at low energy, ω < 100 cm-1 and its spectral weight increases substantially as temperature decreases. This observation and dc-resistivity result show that LTNO has a conductive grain and resistive boundary. Such composite structure provides evidence of the Maxwell-Wagner (MW) mechanism as the origin of the high dielectric constant ε0. We propose a three-phase granular structure and show that this extended MW model explains the observed frequency- and temperature dependence of the dielectric constant as well as the giant value of ε0.
Original language | English |
---|---|
Article number | 172106 |
Pages (from-to) | 1-4 |
Number of pages | 4 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 70 |
Issue number | 17 |
DOIs | |
State | Published - Nov 2004 |