PHOSPHOTELLURIC MATERIAL USED AS 10.6 ΜM RADIATION ABSORBER FOR CARBON DIOXIDE LASER

The invention relates to a phosphotelluric material to be used as a 10.6 μm radiation absorber for the CO2 carbon dioxide laser, due to its chemical, mechanical and thermal stability superior to the currently used silica glasses and to a process for preparing the same. According to the invention, the phosphotelluric material has the following composition: 20% TeO2 + 40% ZnO2 + 40% P2O5 and a density superior to silica glasses of 3.33 g/cm3 compared to 2.47 g/cm3 in the case of neutral Schott NG 1 filters, it has an adsorption coefficient of 48...50 cm-1 at a wavelength of 10.6 μm (945 cm-1), compared to the neutral Schott NG 1 filters which have a coefficient of 10...20 cm-1, the phosphotelluric material having a thermal diffusivity higher than 0.44 W*m-1*K-1 at 27°C and 0.7 W*m-1*K-1 at 450°C compared to the thermal diffusivity of 0.28 W*m-1*K-1 of Schott NG 1 filters, it exhibits a specific heat of 0.455 J*g-1*K-1 at 27°C and 0.78 J*g-1*K-1 at 450°C compared to 0.7J*g-1*K-1 of the Schott NG 1 filters and a short heat transfer time ranging between 0.59 μs at temperatures above 500...550°C and 0.64 μs at 27°C. The claimed preparation process uses the melt over-cooling method, using oxides of metals with purity >99%, which are weighed and placed in an alumina crucible, as follows: firstly P2O5, TeO2 and finally ZnO2, so as the evaporation of P2O5 at 1200°C to be minimal, the crucible is covered with an alumina lid and thermally treated at a heating rate of 6°C/min up to 400°C where the point of transition towards the amorphous state is situated and of 3°C/min until reaching 1200°C where it is held for 30 min, after which the melt is poured into a cylindrical graphite crucible previously heated to 550...600°C, followed by natural cooling down to the room temperature and by sample cutting into discs of 12 mm diameter and thickness ranging between 0.85...1 mm. Invenţia se referă la un material fosfoteluric folosit ca absorber de radiaaţie 10,6 μm pentru laserul cu dioxid de carbon CO2 datorită stabilităţii chimice, mecanice şi termice superioare sticlelor silicatice utilizate în prezent şi la un procedeu de obţinere a acestuia. Materialul fosfoteluric conform invenţiei are următoarea compoziţie 20% TeO2 + 40% ZnO2 + 40% P2O5 şi o densitate superioară sticlelor silicatice de 3,33 g/cm3 comparativ cu 2,47 g/cm3 în cazul filtrelor Schott NG 1 neutre, prezintă coeficient de adsorbţie de 48...50 cm-1 la lungimea de undă de 10,6 μm (945 cm-1), faţă de filtrele Schot