Optical Activity of Ferroelectric 5PbO·3GeO2 Single Crystals

Abstract

Optical rotatory power (ρ = ± 5°35′/mm for λ = 6328 Å) was found in the Czochralski‐grown ferroelectric crystal 5PbO·3GeO₂. Reversal of the ferroelectric spontaneous polarization P_s caused the enantiomorphic transformation of the crystal and consequently the change in the sign of the optical rotatory power. The gyration coefficient g₃₃ was found to fit the equation g₃₃ = γ₃₃P_s, where γ₃₃ is the electrogyration tensor in the paraelectric phase.