One of the key factors that limit the high-power applications for a type II superconductor is the irreversibility line H_irr(T), which reflects the very boundary of resistive dissipation in the phase diagram of magnetic field versus temperature. In cuprate family, the Y-, Bi-, Hg-, and Tl-based systems have superconducting transition temperatures exceeding the liquid nitrogen boiling temperature (~77 K). However, the toxic elements Hg and Tl in the latter two systems strongly constrain the applications. The best perspective so far is relying on the YBa₂Cu₃O_7-δ (T_c ≈ 90 K) system, which is nontoxic and has a relatively high irreversibility magnetic field. We report the study of a nontoxic superconductor (Cu,C)Ba₂Ca₃Cu₄O_11+δ with T_c = 116 K. We found that the irreversibility magnetic field is extremely high, and it thus provides great potential for applications above the liquid nitrogen temperature.

中文翻译：

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无毒铜酸盐超导体（Cu，C）Ba2Ca3Cu4O11 +δ中前所未有的高不可逆线。

限制II型超导体大功率应用的关键因素之一是不可逆线H _irr（T），它在磁场与温度的相图中反映了电阻耗散的边界。在铜酸盐系列中，基于Y，Bi，Hg和Tl的系统的超导转变温度超过了液氮沸腾温度（〜77 K）。但是，后两个系统中的有毒元素Hg和Tl强烈限制了其应用。最好透视到目前为止是依靠的YBa ₂的Cu ₃ ö _7-δ（Ť _Ç≈90 K）系统，该系统无毒且具有相对较高的不可逆磁场。我们报告了对无毒超导体（Cu，C）Ba ₂ Ca ₃ Cu ₄ O _{11 +δ的研究}，其T _c = 116K。我们发现不可逆磁场非常高，因此为上述应用提供了巨大潜力液氮温度。