Full-relativistic calculations of the SrTiO3 carrier effective masses and complex dielectric function

Abstract

We perform fully relativistic band-structure calculations for cubic SrTiO3, which are used to obtain carrier effective masses and the frequency behavior of its complex dielectric function ε(ω). The obtained values and anisotropy of the carrier effective masses are shown to be highly influenced by the relativistic contributions. In order to evaluate the static dielectric constant, the low-frequency behavior of ε(ω) is obtained by taking into account also the optical phonon contributions to the imaginary part of ε(ω), adopting a simplified classical oscillator dispersion model. It is found that the phonon contribution leads to about 240 times (at T=85 K) the value of the bare electronic contribution to the dielectric constant. The calculated temperature dependence of the dielectric constant is shown to be consistent with that observed in bulk SrTiO3 static permittivity measurements.

Structure and correlation effects in semiconductingSrTiO3

“…The thermoelectricity is directly related to the effective mass, which has been measured by different experimental methods 5,17,18,32 and rarely compared with calculations. 6,33 Differences between our observed value of effective mass and the calculated values suggest the need for improved electronic-structure calculations and further investigation of STO with different doping. In addition, the thermoelectric properties have been previously associated with strong correlation.…”

First principle electronic, structural, elastic, and optical properties of strontium titanate

“…One may argue that relativistic effects are important for the description of SrTiO 3 . As was noted by Marques et al, 57 relativistic effects are only important for the description of the high-κ dielectric band structure. Their calculated, relativistic and non-relativistic band structure for SrTiO 3 , up to an energy of 5 eV for the valence and conduction bands, respectively, are almost identical.…”

Strain effects on the electronic structure of SrTiO3: Toward high electron mobilities

“…For example, reported experimental 5,6 and theoretical [7][8][9][10] values for the electron effective mass range from 1.0m 0 to 16m 0 .…”