Effect of SrTiO 3 content on the growth of (100− x )(K 0.5 Na 0.5 )NbO 3 – x SrTiO 3 lead-free piezoelectric single crystals grown by the solid-state crystal growth method

Abstract

In the present work, the single crystal growth by solid-state crystal growth of (100−x)(K_0.5Na_0.5)NbO₃–xSrTiO₃, where x = 0,1,2,3 mol-%, has been examined in order to study the effect of SrTiO₃ content on single crystal growth. Powders were prepared by the conventional mixed oxide method. <001> KTaO₃ seed crystals were buried in the powders, pressed into pellets and sintered at 1100°C for 1, 3, 5 and 10 h. Single crystals of the ceramic compositions grew onto the seeds. For the (K_0.5Na_0.5)NbO₃ sample, both single crystal growth and abnormal grain growth in the matrix began to take place within 1 h. As the amount of SrTiO₃ increased, the onset of both single crystal growth and abnormal grain growth were delayed. The effect of SrTiO₃ addition on the single crystal and matrix grain growth behaviour is explained in terms of the mixed control theory of grain growth.