Synthesis of size- and structure-controlled Ge₂Sb ₂Te₅ nanoparticles

Pulsed laser ablation of Ge₂Sb₂Te₅ target materials at approximately 400 Pa of ambient argon gas produces amorphous nanoparticles with a size distribution of from 4 to 30 nm. Thermal treatment of the nanoparticles in their aerosol states crystallizes the particles to both a hexagonal structure and a face-centered cubic structure at 300°C, while only a face-centered cubic structure results at 400°C. The crystallized nanoparticles were then size-classified by a differential mobility analyzer to produce size- and structure-controlled Ge₂Sb₂Te ₅ nanoparticles. The particles are revealed to consist of germanium, antimony and tellurium by composition analysis using energy dispersive X-ray spectroscopy.