FERROELECTRIC AND OPTICAL PROPERTIES OF KSr2Nb5O15

Abstract
A new transparent tetragonal crystal, KSr2Nb5O15, 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 cm/V and ε is approximately 1,000.