INSTALLATION FOR THE SYNTHESIS OF CARBON NANOSTRUCTURES BY PULSED LASER ABLATION AND NEW METHOD FOR PREPARING THE ABLATION TARGET

摘要

The invention relates to an installation for the synthesis of carbon nanostructures by pulsed laser ablation and to a method for preparing the ablation targets. The claimed installation comprises: a high temperature electric furnace representing the system for heating a synthesis chamber, an external quartz tube, which represents the external wall for defining the synthesis chamber enclosure, closed at its ends by means of two flanges: a front one and a back one, inside said tube there being placed: an internal quartz tube which serves as an insertion and guide channel for a working gas on the surface of the ablation target, a system for supporting and rotating the ablation target consisting of a graphite rod on which there is fastened by screwing an element for embedding the ablation target, the free end of the rod being fastened in the back flange by screwing in a rotary element which makes the connection with the exterior of the synthesis chamber, and also a cone for collecting the ablation products, cooled with water, at the inner side of which there are placed two copper pipes for introducing and extracting the cooling water, the cone being fastened on the back flange by means of some water connectors, the front flange, in the middle of which there is cut a hole in which there is fixed a T-shaped tube having on an arm an irradiation window and on the other arm there being introduced the working gas for the thermal balance of the external quartz tube, the flange being cooled with water, and the back flange, where there are fastened both the target holder rod and the collecting cone, and a system for exhausting gases and controlling the pressure in the synthesis chamber. The preparation method is based on using a carbon cement as unique graphite precursor in the ablated target, said cement being mixed with some metal catalysts, the resulting mixture being subjected to some heat treatments.