Formation of YxNd1−xBa2Cu3O7−δ (0≤x≤0.9) superconductors from an undercooled melt via aero–acoustic levitation

This paper presents the results of rapid solidification experiments performed on the copper oxide superconductors YxNd1−xBa2Cu3O7−δ (0≤x≤0.9). Spherical rare earth (RE) 123 specimens were levitated in O2 using aero–acoustic levitation (AAL), melted with a laser, undercooled, and solidified. The peritectic transformation temperature for the reaction RE2BaCuO5+liquid→REBa2Cu3O7−δ corresponding to the maximum recalescence temperature during solidification was determined. RE123 was formed directly from the melt for Y–Nd binary alloy compositions with Nd concentration greater than 20% (Y concentration less than 80%). A minimum in the peritectic transformation temperature for the Nd/Y123 system corresponding to a composition Y0.3Nd0.7123 was determined at 66 °C below the peritectic of pure Nd123.