Effect of electric field on the dielectric properties of the Barium Strontium Titanate film

We investigated the tunability of the dielectric characterization of the Ferroelectric Barium Strontium Titanate (Ba0.5Sr0.5TiO3) thin film on the Strontium Titanate substrate by a dc bias electric field through the terahertz time-domain spectroscopy. The tunability of the real part of the permittivity reached up to 74.8% and the imaginary part of the permittivity reached up to 33.6% when the bias electric field up to 30 V. And the results are attributed to the soft mode hardening caused by the electric field.