MgB2 films prepared by rapid annealing method

The experiment for preparing MgB2 thin films by electron beam (e-beam) annealing of Mg–B multilayer is reported. The annealing process lasts less than 1 s, which effectively suppresses the volatility of Mg as well as the reaction of Mg and oxygen. The influence of annealing parameters on the film quality including exposure time, accelerating voltage and beam current is investigated. It is found that e-beam with lower accelerating voltage can acquire MgB2 film with smaller annealing energy density. Also, double e-beam scan annealing process helps to obtain more uniform MgB2 thin films than the single scan. This rapid annealing method synthesizes MgB2 thin films with critical temperature Tc of 35 K and critical current density Jc at 15 K of 7.6 × 106 A cm−2.

► We fabricated MgB2 films by rapid electron beam annealing method.
► The annealing time is limited less than 1 s.
► The rapid annealing method can suppress Mg volatilization and the reaction of Mg and oxygen in the annealing process.
► Different annealing condition was compared for MgB2 films.