Development of HoBCO tapes fabricated by ISD process

Ho/sub 1/Ba/sub 2/Cu/sub 3/O/sub x/ (HoBCO) tapes by using pulsed laser deposition (PLD) have been developed on flexible Ni-alloy substrates. Inclined substrate deposition (ISD) was developed to introduce in-plane alignment for buffer layers. YSZ was deposited by PLD combined with ISD as a buffer layer on Ni-alloy tape. The advantage of ISD is a high growth rate due to the self in-plane alignment without any other assistance. This was demonstrated by using a CeO/sub 2/ buffer layer. A CeO/sub 2/ buffer layer shows high growth rates of 1 - 2 /spl mu/m/min. As for the growth rate of HoBCO, 4 /spl mu/m/min. was confirmed. Scale-up of the PLD system for making a long tape was performed. In this system, a 200 W-KrF excimer laser over 100 h continuous operation, a large deposition chamber including long ramp heater and three 10-in target system, and a reel to reel tape transfer system up to several hundred meters were introduced and combined. The continuous sputtering system for silver layer and O/sub 2/ annealing system were also introduced. By using these systems, a 50 m CeO/sub 2/ buffer was continuously deposited on a Ni-alloy tape. The deposition tape speed was 0.75 m/h, thickness was 2 /spl mu/m, and full-width at half-maximum was 23/spl deg/ in average. By depositing HoBCO on a part of this CeO/sub 2//Ni-alloy tape, Ic = 29 A/cm-width and Jc = 0.27 MA/cm/sup 2/ were demonstrated.