Tungsten bronze structure Sr1-xBaxNb2O6 (SBN) single crystals were grown primarily using the Czochralski method, in which several difficulties were encountered: striation formation and diameter control. Striation formation occurred mainly because of crystal rotation in an asymmetric thermal field and unsteady melt convection driven by thermal buoyancy forces. To optimize the growth conditions, bulk SBN crystals were grown in a furnace with resistance heating elements. The zone of O2 atmosphere for crystal growth is 9.0 cm and the difference of temperature between the melt and the top is 70˚C. According to the growth conditions of the rotation rate, grown SBN became either polycrystalline or composed of single crystals. In the case of as-grown Sr1-xBaxNb2O6 (x = 0.4; 60SBN) single crystals, the color of the crystals was transparent yellowish and the growth axis was the c-axis. The facets of the crystals were of various shapes. The length and diameter of the single crystals was 50~70 mm and 5~10 mm, respectively. Tungsten bronze SBN growth is affected by the temperature profile and the atmosphere of the growing zone. The thermal expansion coefficients on heating and on cooling of the grown SBN single crystals were not matched. These coefficients were thought to influence the phase transition phenomena of SBN.

The growing conditions of barium nitrate Ba(NO3)2 single crystals using the aqueous solution method have been studied. Supersaturation can be calculated by measuring the temperature of the solution and its equilibrium temperature. Supersaturation of Ba(NO3)2 was 0.7% at 32.0˚C and about 3% at 34.0˚C. The obtained single crystals have three kind of morphology: tetrahedral, cubic, and, rarely, dodecahedral. The normal growth rate is proportional to the supersaturation; it is necessary to make the solution below 5% supersaturation in order to obtain transparent Ba(NO3)2 single crystals. The normal growth rate for 1ar11 faces was 2.51×10-6 mm/s for the 0.7% supersaturation condition (32.0˚C), 6.43×10-6 mm/s for the the condition of 3.0% supersaturation, and 7.01×10-6 mm/s for the condition of 5.0% supersaturation. The quality of the grown crystals depends on the nature of the seed, the cooling rate employed, and the agitation of the solution. The faces of the obtained crystals have been identified uising an X-ray diffractometer. The surface diffusion is responsible for the low growth rates of the 1ar11 faces.