Linear electro-optical properties of tetragonal BaTiO3

Abstract

Linear optical susceptibility and clamped linear electro-optical tensor coefficients of tetragonal BaTiO 3 are calculated using a formalism based on bond charge theory. Calculated values are in close agreement with experimental data. The covalent Ti-O bonds constituting distorted TiO 6 octahedral groups are found to be major contributors to the electro-optic coefficients making them more sensitive than the BaO 12 groups for these properties. Orientations of chemical bonds play an important role in determining these properties.

Characterization of BaTi1−xZrxO3 thin films obtained by a soft chemical spin-coating technique

“…Barium titanate ͑BaTiO 3 ͒ is one of the most studied perovskite-type materials, especially due to its potentiality applications such as capacitive and nonvolatile memory cells (DRAMs and FRAMs), electro-optical integrated circuits, pyroelectric devices, etc. [1][2][3] It is well known that homovalent and heterovalent substitutions of barium or titanium ions give rise to various behaviors including relaxor properties, which may appear for some compositiontemperature ranges. [4][5][6] Additions such as strontium are employed to lower the Curie temperature T c , which decreases linearly with the increase of the strontium content.…”

Semi-Experimental Determination of the Linear Clamped Electro-Optical Coefficients of Polar Crystals from Vibrational Spectroscopic Data

“…We have reassigned the published E-mode frequencies of KNO and PTO crystals using parallel mode assignments performed on BTO crystals [46] based on the imaginary frequency peak position (Table 3). The anomalous frequency of the soft mode, which is responsible for the excess of the effective charge, also affects the value of the B kij coefficient through (14). This situation, in conjunction with the lowest frequency mode position (typically less than 100 cm −1 ), can finally be considered as the main physical cause of the outstanding values of the r 51 coefficient of the ABO 3 perovskite crystals.…”

“…The NLO coefficients can be semi-empirically calculated using the bond charge model (BCM) [12]. Based on this model, Shu and Yariv [13] derived some improvements which are currently used for the electro-optical calculation of a large band of NLO crystalline materials [14,15]. Another equivalent model, the bond orbital model (BOM) [16], could also, in principle, be modified to determine the EO coefficients in semiconductors and insulating materials.…”