Ferroelectric and optical properties of KSR₂NB₅O ₁₅

A new transparent tetragonal crystal, KSr2Nb5O 15, of the tungsten bronze type has been found to be ferroelectric with a Curie temperature of ≈160°C. At room temperature the electro-optic coefficient, r∥, is 1.3 × 10-8 cmV and ∥ is approximately 1,000. © 1967 The American Institute of Physics.