Crystal growth of alkali metal ion doped potassium niobate fiber single crystals

Abstract Alkali metal (Na, Rb or Cs) ion doped KNbO3 fiber single crystals are grown using an original pulling down method, to improve their composition change during a crystal growth, by means of co-doping of small ionic size Na and large ionic size Rb or Cs into KNbO3. In spite of the co-doping, single crystals can be grown with orthorhombic single-phase at room temperature, as well as pure KNbO3. Their electric properties, such as impedance, are changed depending on the doping ions. Na and Rb co-doped KNbO3 is promising Pb free ferroelectric and piezoelectric crystals.