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Ion Beam Assisted Deposition (IBAD) of Magnesium Oxide (MgO) has been proven to be a viable route for producing template films used to deposit high quality YBCO coated conductors on flexible polycrystalline metal substrates. Here we will discuss improvements in this process using a dual ion assist beam configuration. Dual ion assist beam deposition of MgO reduces the requirements for substrate surface finishing while maintaining comparable film quality (phi scan full-width at half-maximum values between 7 and 8 degrees). Furthermore, this adaptation of the IBAD process eliminates the degradation of MgO texture observed in thick IBAD MgO films deposited on silicon nitride. We have deposited films up to 50 nanometers thick without degradation of in-plane texture. Increasing the MgO thickness increases the chemical stability of the template layer and can eliminate the necessity for subsequent buffer layers or the application of the homoepitaxial MgO layer needed to stabilize the thin, conventional IBAD MgO layer. Initial results of subsequently deposited YBCO on these dual assist ion beam MgO templates are quite promising. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

A study of some defect structures in Y[sub 1]Ba[sub 2]Cu[sub 3]O[sub 7] (Y-123) coated conductors based on ion-beam-assisted-deposition (IBAD) of yttria-stabilized zirconia (YSZ) on nickel alloy substrates is presented. Defect structures can originate anywhere in the coated conductor architecture. Defects can be additive and propagate through the entire film structure to affect the growth, orientation, and properties of the superconducting film. Interfacial reactions between Y-123 and the underlying buffer layer and the corresponding effects on the transport properties of the films can be controlled with the thickness of the underlying buffer layer. With a 90Å ceria buffer layer on an IBAD YSZ coated metal substrate, a J[sub c] value of 1.7 MA/cm² (self-field, 75K) was obtained in a 1.5µm thick Y-123 film. [ABSTRACT FROM AUTHOR]