Laser-Assisted Growth of Superconducting MgB2 Films in an In Situ Annealing Process Using a Stoichiometric Target

Abstract

A superconducting MgB2 film with a superconducting transition temperature of ∼36 K was successfully prepared on an MgO substrate by pulsed-laser ablation from a stoichiometric MgB2 target. A multilayer deposition process involving interposed Mg-rich layers was performed at 200°C by controlling the laser energy density in order to maintain the correct stoichiometry, and followed by an in situ annealing process at temperature ranging from 700° to 900°C. It was found that smooth, fine-grained films with superconducting transition temperatures of 24–36 K could be obtained from in situ annealing of the as-deposited multilayer at 900°C without excess Mg addition.