Phase and Morphology Control of Magnesium Nanoparticles via Lithium Doping

We present experimental phase stability and particle morphology changes of metallic magnesium powders with the incorporation of lithium and gold as dopant and oxidation barrier coating, respectively. The crystal structure of the magnesium powders changes from hexagonal close-packed to body-centered cubic as the concentration of lithium dopant is increased. The phase change influences powder morphology and results in a modification of the powder shape from spherical to elongated rods, as confirmed by transmission electron microscopy. The crystallite size also decreases from around 100 to 30 nm. Differential scanning calorimetry analyses show that the powders with lithium transform from amorphous to crystalline at a lower temperature in comparison to powders without lithium. The results provide important insights into the formation of body-centered cubic magnesium alloys.