화학공학소재연구정보센터
Journal of Crystal Growth, Vol.229, No.1, 396-400, 2001
Crystal growth of Bi-2(Sr,Nd/Sm)(2)CuOy and their superconductivity
Bi(2)Sr(2-x)Ln(x)CuO(y) (Ln = Nd, Sm) was synthesized in the range of x = 0.2-0.6 and a single phase was obtained in the range of x = 0.3-0.6. A diamagnetic signal was observed for x = 0.2-0.6 and the maximum T-c of 23 K for Nd3+ and 17 K for Sm3+ was obtained around x = 0.5 and 0.4, respectively. Single crystals of Bi(2)Sr(2-x)Ln(x)CuO(y) (Ln =Nd, Sm) were successfully grown by the self-flux method from the melt of stoichiometric composition. DTA was used to determine the thermal cycle. The as-grown crystal from the melt of Bi2Sr1.6CuOy was Bi1.8Sr1.1Nd0.7CuOy with dimensions over 2mm and exhibited superconductivity at T-c similar to 20K. The crystal growth of Bi2Sr2-xSmx,CuOy was examined for the stoichiometric melt of Bi2Sr1.5Sm0.5CuOy However, we could not observe single crystal with 2 2 0 1 structure. The crystal had 2 2 1 2 structure and showed no superconductivity.