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تسجيل مستخدم جديدEvidence that the upper critical field of Nb3Sn is independent of whether it is cubic or tetragonal
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Although 2011 marks the 50th anniversary of Nb3Sn as the first high field superconductor, real understanding of its upper critical field behavior {mu}0Hc2 is incomplete. Here we show surprising {mu}0Hc2 data on highly homogeneous bulk samples examined both by small-current, transport and by volumetric-averaging specific heat and the reversible magnetization techniques, which exhibit identical upper critical field {mu}0Hc2(0.3 K) ~ 29{pm} 0.2 T with or without undergoing the cubic to tetragonal transition, a result in strong contrast to widely used multiple-source data compilations that show a strong depression of {mu}0Hc2(0K) from 29 T to 21.4 T in the tetragonal state.
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