Synthesis and characterization of nano-sized MgB₂ powder by spray pyrolysis method

The nano-sized MgB₂ powder was prepared by spray pyrolysis method in order to improve its flux pinning properties by increasing the number of grain boundaries. MgB₂ powder was synthesized using spray pyrolysis technique followed by a post-annealing process without excessive magnesium addition. The feed solution was prepared by dissolving the correct amounts of Boric acid and Magnesium acetate tetrahydrate into distillated water and ethanol solution and the overall concentration were fixed at 0.1 mol/L. During the decomposition, 96% Ar-4% H₂ was used as carrier gas. The collected powders were characterized by X-ray diffraction, scanning electron microscopy, particle size analyzer, and physical property measurement system. The particles prepared by spray pyrolysis showed spherical morphology and uniform distribution with the average size of 1 μm. The onset of superconducting T_c for synthesized MgB₂ powder was around 38 K.