Fabrication of micro and submicro Y–Ba–Cu–O particles by excimer laser processing

Abstract

We have investigated the crystallization of amorphous Y–Ba–Cu–O films with pulsed laser irradiation. The Y–Ba–Cu–O films were prepared on Si (001) substrates by pulsed laser deposition at room temperature. The microstructure and surface morphology of the films during the crystallization process were studied by x-ray diffraction and scanning electron microscopy. Micro or submicro Y–Ba–Cu–O crystalline particles can be obtained with variant laser pulses and energy densities. The particles have half-spherical or even spherical shapes on the film surfaces, and the saturated particle sizes were found to be determined by the film thickness.

Unique redox properties in defective CeO2-x nanocrystallines synthesized by laser melting

“…The laser focused upon the pellets' top surface and the spot (75 μm in diameter and 50 W in laser power) moved along a scheduled path to fully melt the entire area. The energy density of the laser is about 600 J cm −2 , which is much higher than that normally used in laser ablation or annealing of ceramics [13,14]. The surface zone treated by laser was then carefully removed and ground into powder manually for characterization, and will be marked as "LT" in the following text.…”