Growth and characterization of ferroelectric SrBi$_2$Ta$_2$O$_9$ single crystals via high-temperature self-flux solution method

SrBi$_2$Ta$_2$O$_9$ (SBT) single crystals were produced by high temperature self-flux solution method using a Bi$_2$O$_3$ flux modified with B$_2$O$_3$. The processing conditions were optimized to obtain large and translucent SBT crystals with a layered habit and typical dimensions of approximately 7 $\times$ 5 $\times$ 0.2 mm. X-ray diffraction and x-ray topography measurements revealed the major faces of the crystals with natural rectangular platelet morphology are perfectly (001)-orientated with edges directed along the [110] directions. High quality of the crystals was confirmed by rocking curves (half width of 0.04$^\circ$ for the (0 0 18) reflection) and by ferroelectric measurements. The anisotropy in the dielectic and ferroelectric properties was investigated both along the [110] ($ab$-plane) and the [001] ($c$-axis) directions. The growth mechanism, morphology and dielectric anisotropy of the SBT crystal platelets are discussed based on its crystallographic structure.