Microwave-enabled flash heating and cooling for synthesizing single-phase multi-principal element alloy nanoparticles

It is challenging to synthesize single-phase alloy nanoparticles made of multiple principal elements, including thermodynamically immiscible combinations, because of phase separation at near-equilibrium conditions. Kinetic control over mixing multiple elements and crystallization at far-equilibrium conditions represents a strategy to overcome thermodynamic limitations. Efficient absorption of high-power microwave pulse in a substance dispersed in a microwave-transparent medium can lead to selective “flash heating” of the substance to very high temperatures followed by “flash cooling” due to rapid heat dissipation to the surrounding medium. Such flash heating/cooling creates far-equilibrium conditions to synthesize multi-principal element alloy nanoparticles.