Ultrafast, Energy-Efficient Synthesis of Intermetallics; Microwave-Induced Metal Plasma (MIMP) Synthesis of Mg₂Sn

Magnesium stannide, Mg₂Sn, can be synthesized from the elements using microwaves over minute time scales in the solid state. The effects of Mg content, pressure and microwave irradiation time were investigated and single phase Mg₂Sn was produced in 1 min under only 200 W of incident irradiation in vacuuo (P < 10^-6 mbar). The fine Mg and Sn metal powders both couple efficiently with the microwave field under a vacuum, heating up rapidly and generating plasma. The metal plasma formation is shown to be essential for reaction completion and promotes the enhanced kinetics of the reaction via one or more possible reaction pathways to sintered Mg₂Sn. This approach provides a simple, ultrafast, sustainable, and energy-efficient route to phase-pure Mg₂Sn, a material that is extremely challenging to make at high purity by conventional methods. The MIMP formalism should be applicable to many other metalloid materials of this and other types.