Annealing effect on the irreversibility line in (Cu,C)Ba₂Ca₂Cu₃O_y

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• 作者：Akira Iyo ; Yasumoto Tanaka ; Norio Terada ; Madoka Tokumoto ; Hideo Ihara
• 刊名：Physica B
• 出版年：2000
• 出版时间：July 2000
• 年：2000
• 卷：284-288
• 期：Part 1
• 页码：867-868
• 全文大小：102 K

文摘

Annealing effects on irreversibility fields (H_irr) and physical properties in high-quality (Cu,C)Ba₂Ca₂Cu₃O_y ((Cu,C)-1223) samples have been investigated. The T_c of (Cu,C)-1223 increased from 70 K (as-prepared) to 120 K by annealing up to 550 °C in a nitrogen gas. The decomposition temperature (550°C) and the annealing effect on T_c of (Cu,C)-1223 were found to be different from that in C-free samples, which may be due to stability of carbonates in the (Cu,C)-site. The slightly overdoped sample (T_c=111 K) showed high H_irr (=9.4 T) at 77 K rather than the optimal-doped sample (T_c=120 K). This indicates that control of doping level as well as T_c is important to enhance the H_irr at 77 K.