Observation of TO1 soft mode in SrTiO3 films by terahertz time domain spectroscopy

Abstract

Articles you may be interested inEffect of stoichiometry on the dielectric properties and soft mode behavior of strained epitaxial SrTiO3 thin films on DyScO3 substrates

SrTi1−xFexO3nanoparticle: a study of structural, optical, impedance and magnetic properties

“…The other abundantly observed features are related to the additional active modes. These optical responses show good consistency with the previous work on SrTiO 3 thin film and ceramic samples [13][14][15][16]. Because of measuring scale limit, we cannot detect TO 1 in our spectra.…”

Thickness dependence of the soft ferroelectric mode in SrTiO3 thin films deposited on MgO

“…This corresponds to the reported size effect of the SrTiO 3 thin films [4,7,8]. In addition, the soft mode frequency in the 460 nm thin film at low temperature is slightly higher than that of the 1046 nm thin film, which indicates the relaxation of the soft mode hardening.…”

“…The mechanism is not fully understood, because of the complex contributions of stress from the substrate and thermal expansion mismatch, defects and impurities, surfaces, interfaces and grain boundaries. In this work, we demonstrate that the recently developed broadband terahertz time-domain spectroscopy (THz-TDS) is very useful to study the size effects of the dielectric thin films, because the complex dielectric constant can be obtained without Kramers-Kronig relation that essentially needs the reflectivity at all frequencies [6][7][8]. We have measured thickness dependence of the complex dielectric constant from 0.1 to 8 THz of SrTiO 3 thin films, and the obtained result may shed an insight into the mechanism of the size effect in SrTiO 3 thin films.…”

Terahertz Response of Ferroelectric Nanofibers

“…Particularly, since the discovery of soft phonon mode in SrTiO 3 and BaTiO 3 , there has been a great interest and challenge in understanding the relationship between the dielectric properties and the phonon response of these materials in the far-infrared spectral region. [8][9][10][11][12] In spite of the involved numerous research with exploited rich properties and important applications, SrTiO 3 and BaTiO 3 are by far less well understood due to the complexity of structures, especially for their nanoscale structures. * Author to whom correspondence should be addressed.…”