High production rate of IBAD-MgO buffered substrate

Abstract

The conventional IBAD (Ion Beam Assisted Deposition) process using fluorite materials yields low production rates, resulting in high production cost, which reduces the motivation for practical application in spite of its high quality. The IBAD process using rock salt materials, e.g. MgO, is well known as a strong candidate of practical application due to its potential of high production rate and high in-plane grain alignment. In this work, the IBAD-MgO process was investigated for a newly developed architecture of PLD (Pulsed Laser Deposition)-CeO 2/sputter-LMO (LaMnO 3)/IBAD-MgO/sputter-GZO (Gd 2Zr 2O 7)/Hastelloy TM to make long buffered metal tapes with high properties and a high production rate. The 50 m-long IBAD-MgO substrates with about 4° of Δ φCeO 2 in an XRD φ scan could be fabricated repeatedly. A GdBCO (GdBa 2Cu 3O x ) layer deposited on the buffered substrate showed the minimum I c value of 325 A/cm-w in a 41 m-long tape. Almost of the tape showed 500–600 A/cm-w of I c value. The deposition time for the IBAD-MgO layer was 60 s which was about 2 orders of magnitude shorter than the conventional IBAD process. The production rate of 24 m/h was realized at the IBAD-MgO process to fabricate the GdBCO coated conductor with high J c and I c properties.