Investigation of thermal behavior and crystal growth of iron pnictides using Sn flux

Study of the thermal behavior of iron pnictides mixed with Sn flux was performed using differential thermal analysis (DTA) to obtain the optimum conditions for crystal growth. Our results indicate that both polycrystalline powders of BaFe2As2/Ba1−xKxFe2As2 and initial mixtures of pure metals of Ba, Fe, and As can be used to grow single crystals. Analysis of the DTA indicates that crystallization temperature decreases with the increase in Sn flux content in the initial mixtures. Single crystals as large as several cm3 were grown under the modified growth conditions and show a sharp superconducting transition at Tc∼30 K