Correlation between thermal properties, growth parameters and low segregation coefficient in (K, Na)NbO3-based growth by Bridgman-Stockbarger route

In order to achieve optimized growth conditions to reduce the compositional segregation in (K,Na)NbO3-based crystals produced by the vertical Bridgman-Stockbarger (VB-S) method, both a complete previous analysis of the thermal properties of the precursor oxides and a suitable choice of the dimensions of the crucible were made based on theoretical models proposed in the literature. By following this approach, chemical analysis of the as-grown crystals revealed very small effective segregation coefficients in the radial and longitudinal directions of the as-grown crystals. The obtained results revealed that is possible to grow single crystals by VB-S even for incongruent compounds, through a suitable establishment of the growth parameters adjusted according to the thermal properties of the piezoelectric oxide and the relative dimensions of the crucible. [Display omitted]