Effect of nominal copper concentration in yttrium barium copper oxide $(YBa_2Cu_{3pmx}O_{7-delta} )$ on the superconducting transition

摘要

Variation of [Cu] in the nominal compn. $YBa_2Cu_{3pmx}O_{7-delta}$ markedly influences the superconducting transition. The transition occurs at the highest temp. with the lowest width, when $x = 0.25$