We present THz conductivity of LaAlO3 (LAO) as a function of temperature and annealing, using terahertz time-domain spectroscopy (THz-TDS). We observed that, after annealing, spectral weight redistribution occurs, such that the real conductivity ?1(ω) changed from a featureless and almost frequency-independent spectrum, into one where peaks occur near the phonon frequencies. These phonon frequencies increase with increasing temperature.We attribute the appearance of these absorption peaks to the diffusion and relocation of oxygen vacancies. The dielectric functions of annealed LAO are well fitted with the Drude-Lorentz model.
|Original language||English (US)|
|State||Published - Mar 2012|
Bibliographical noteFunding Information:
The authors acknowledge support from Singapore Ministry of Education Academic Research Fund Tier 2 (Grant No. ARC 23/08), as well as the National Research Foundation Competitive Research Programme (Grant No. NRF-CRP4-2008-04). We thank Venky Venkatesan and Sankar Dhar for useful discussions.
ASJC Scopus subject areas
- Physics and Astronomy(all)