Bridgman growth and properties of potassium lithium niobate single crystals

Transparent KLN crystals 10mm in diameter and 25 to 45mm in length have bee n grown by the modified vertical Bridgman technique from different melts in the range of 30-35mol% K2O, 17 similar to 23mol% Li2O and 43 similar to 50 mol% Nb2O5 The growth conditions are a growth rate of less than 0.25 mm/hr, temperature gradient in solid-liquid interface of 2-3 degrees C/mm and gro wth direction of [110]. As-grown KLN crystals have tetragonal tungsten bron ze structure. Most of the as-grown crystals do not crack when cooling throu gh the paraelectric/ferroelectric phase transition. 180 degrees domain stru ctures are observed after the KLN crystal was etched in boiling 2HNO(3):HF. Dielectric properties and transmission spectrum of the as-grown KLN crysta ls are measured.