Structural and intrinsic Josephson properties of Bi2Sr2Ca1−yYyCu2O8+δ single crystal

• Single crystals of yttrium-doped BSCCO (BSCYCO) were grown by a self-flux method.
• Tc and c-axis lattice constant of BSCYCO were controlled by the substitution of Y.
• A multibranch structure was observed up to y = 0.10 (Bi2Sr2Ca1−yYyCu2O8+δ).
• The BSCYCO mesa has higher maximum voltage compared with nondoped BSCCO.

In this study, Bi2Sr2Ca1−yYyCu2O8+δ (BSCYCO) single crystals with yttrium doping content of y = 0–0.30 were synthesized by a self-flux method. The critical temperature and c-axis lattice constant of BSCYCO were controlled by the substitution of yttrium at the calcium site. A 290 × 90 × 0.4 µm3 mesa structure was fabricated using photolithography and argon-ion milling. A multibranch structure in current–voltage characteristics was successfully observed for mesas of BSCYCO (y = 0–0.10). The critical current of intrinsic Josephson junctions (IJJs) in BSCYCO mesas was systematically investigated.