Pulling rate and current intensity competition in an electrically assisted laser floatingzone

Abstract

Bi–Sr–Ca–Cu–O (BSCCO) superconducting fibres were grown using the laser floating zonetechnique assisted by a dc electrical current (electrically assisted laser floatingzone—EALFZ process). The simultaneous effect of pulling rate and applied currentintensity was evaluated on the premises of the: (i) elemental partition coefficient betweensolid and molten zone; (ii) phase development; (iii) crystal size and alignment degree of theprimary and superconducting phases; (iv) phase transformation during heat treatmentand (v) superconducting properties. The highest critical current density value (JC = 2240 A cm−2) was obtained for the fibres pulled at intermediate pulling rates (75 mm h−1) grown under a maximum dc electric current intensity (200 mA).