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

In the present work, the single crystal growth by solid-state crystal growth of (100−x)(K0.5Na0.5)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 (K0.5Na0.5)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.