Two-level growth of potassium niobate KNbO3 single crystals: A new growth method for ABO3-type materials

Abstract

Based on our recent study on the directional growth of KNbO3 single crystals, a new growth scheme called the two-level growth (TLG) has been developed. By using the TLG method, high quality transparent KNbO3 single crystals can be prepared with high reproducibility. The technique includes two growth stages. In level-one growth, a dimensionally defined (shaped) KNbO3 seed with high crystal perfection is fabricated. The target crystal with desired dimensions and an architectural structure can be obtained in the second level of the growth. A process flow chart for the TLG method has been presented and six representative types of the growths have been introduced. Generally, crystals grown by TLG have much less crystal imperfections than those obtained from the conventional way. Technological merits of the TLG scheme have been studied, indicating that this growth scheme can also be employed to other oxide perovskite ABO3 single crystal growths.