CHIN Ken Tohoku University, Assistant Professor, 電気通信研究所, 助教授 (90241588)
YAMASHITA Tsutomu Tohoku University, Professor, 未来科学技術共同研究センター, 教授 (30006259)
ITO Hidenobu Faculty of Engineering, Assistant Professor, 工学部, 助教授 (90113703)
|Budget Amount *help
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2002: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2001: ¥2,600,000 (Direct Cost: ¥2,600,000)
Recent attention has been on single crystal whiskers of high T_ο superconductors because of their useful characteristics such as perfect crystallinity, absence of dislocations, peculiar dimensions with extremely small cross sections, and excellent superconducting properties. Developments suggest that the high-T_ο whiskers are useful in the fabrication of electronic devices with high frequency THz band using intrinsic Josephson effects and related phenomena, such as Josephson plasma oscillations.
Bi_2Sr_2CaCu_2O_χ (Bi-2212), (BiPb)_2Sr_2Ca_2Cu_3O_<10+δ> ((BiPb)-2223) and R_1Ba_2Cu_3O_χ (R-123)(R=Y, La, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu) single-crystal whiskers were grown from annealing sintered Te and Ca doped precursor pellets. The optimal precursor composition is Ca-rich Bi_2Sr_2Ca_2Cu_2Te_<0. 5>O_χ for Bi-2212, mixture of single-phase (BiPb)-2223 with 0.5TeO_2 for Bi-2223, and R_1Ba_2Cu_3Te_<0.5>Ca_<1.0>O_χ for R-123. The whiskers have excellent crystallinity with contain no Te element, and exhibit interesting intrinsic Josephson effects along the c axis.