Formation of ErAs Nanoparticles by Pulsed Laser Ablation of Pressed Powder Targets

We investigate the optimal growth conditions for ErAs nanoparticle powders by nanosecond pulsed laser ablation in a He environment from elemental pressed powder targets. Incongruent ablation of the target due to differences in vaporization enthalpies is observed, and compensation for these differences is explored through altering target composition. The preferential ablation of As from the Er-As pressed powder targets appears to diminish over time, resulting in the reduced impact of differing vaporization enthalpies. Additionally, the influence of collection distance is investigated as a means to control crystallite size and powder composition. Particle size is shown to increase with collection distance and appears to reach a plateau as the beaker diameter becomes much larger than the plume size.