Synthesis of powders and films using a new laser ablation technique

A novel method to produce powders and films from ceramic targets is present ed. It is shown that the laser spark atomizer (LINA-SPARK(TM)), LSA, combin es the advantages of operating at atmospheric pressure and ambient temperat ure to produce highly uniform films with a web-like structure which can be deposited at relatively high deposition rates (ca. 1 mu m.min(-1)). The pre paration of powder particles and coating starting from commercial ceramic s pecimen (Al2O3) is investigated. Highly agglomerated nanopowders and homoge neous mesoporous coatings forming a web-like structure are prepared using t his new technique. The formation of the nanoparticles is explained followin g a liquefaction process which generates an aerosol, followed by the coolin g/solidification of the droplets which results in the formation of a smoke. The general dynamic of both the aerosol and the smoke favors the aggregati on process and micrometer-sized fractal-like particles are formed. The lase r spark atomizer can be used to produce highly mesoporous thick films. The porosity can be modified by the carrier gas flow rate thus enabling for a c ontrol of the microstructure of the coatings which make these nanoparticula te thick films suitable candidates for application in membrane technology, catalysis and lithium ion batteries. ZrO2 and SnO2 nanoparticulate thick fi lms are also synthesized successfully using this new process with quite ide ntical microstructure. (C) 2000 Acta Metallurgica Inc.