High-speed deposition of high-quality RE123 films by a PLD system with hot-wall heating

Abstract

We have studied the use of a hot-wall heating system for producing GdBa2Cu3O7−X (Gd123) films with large critical current (Ic), stably, at high speed, by a pulsed laser deposition (PLD) method. We achieved a material yield from the PLD system with hot-wall heating of about 50% through optimization of the evaporation conditions. With the PLD system, we were able to fabricate a Gd123 film about 20 cm long with a high Ic of 997 A (77 K, self-field) at about 6 µm thickness. The maximum Ic that we achieved for a Gd123 film about 2 cm long was 1040 A (77 K, self-field) at about 6 µm thickness. Furthermore, we were able to form a Gd123 film about 1 µm thick and 20 cm long with an Ic of 352 A (77 K, self-field) at a high speed of 60 m h−1 using high laser power. For the production of long conductors coated with RE123 (REBa2Cu3O7−X, where RE stands for rare earth) using hot-wall heating, it was found that RE123 coated conductors over 100 m long with Ic of over 200 A had uniform Ic distributions with ± 2% variations in the direction of the length.