Synthesis of anisometric KSr2Nb5O15 particles in the SrNb2O6–Nb2O5–KCl system

Abstract

Anisometric and agglomerate-free template particles are important for fabrication of grain-oriented ceramics. In the present work, preparation of acicular KSr2Nb5O15 (KSN) particles was firstly explored in the SrNb2O6–Nb2O5–KCl system by molten salt synthesis (MSS) method. It was found that the molar ratio of SrNb2O6 to Nb2O5, the amount of KCl salt and synthesis time could significantly affect the phase structure and morphology of KSN particles. When calcined at 1,150 °C for 6 h with the molar ratio of SrNb2O6 to Nb2O5 was 1 and the weight ratio of salt to oxide source was 1.50, pure KSN particles with well-developed acicular morphology were successfully obtained in this system. They were agglomerate-free and with proper scale in the size range of 5–30 μm, which made them the ideal templates for fabricating textured ceramics. In addition, some new reaction and growth mechanisms were proposed in this work.