Dual Ion Assist Beam Deposition of Magnesium Oxide for Coated Conductors

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