The electro-optic properties of epitaxial KTaxNb1-xO3 thin films were measured throughout the entire solid solution range, 0≤x≤1. For unpoled films, electro-optic coefficients measured at 100kHz exhibited an average value of 4.7pm/V at x=0 and a monotonic decrease with increasing Ta concentration. Upon poling with a DC bias field to align ferroelectric domains, the electro-optic response of the films increased. Under the DC bias field, the electro-optic coefficient exhibited two local maxima with respect to composition of 40 and 30pm/V at x≈0.20 and x≈0.70, respectively. These maxima correspond to the room temperature phase boundaries of the KTaxNb1-xO3 thin film system. The observation of a sharp maximum in the DC bias field response of the EO effect at x≈0.70 gives evidence of easy domain alignment at the ferroelectric phase boundary.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering