Home – Home – Jornals – Chemistry for Sustainable Development 2014 number 5

Preliminary mechanical treatment of a mixture of yttrium oxide and lithium carbonate in a planetary mill intensifies subsequent thermal synthesis of LiYO₂ and allows reducing the temperature of complete transformation to 850 °C. The synthesized powder can be used as an additive that accelerates sintering of aluminium nitride without additional grinding. Mechanical treatment of the mixture results in the formation of aggregates that are frameworks of Y₂O₃ filled with lithium carbonate. Due to this, the surface of contact between reagents increases. However, with excess over some limiting acceleration developed in the mill, the framework densifies, and extrusion of the second component is observed. As a consequence, the reactivity of the mixture decreases, especially if lithium carbonate is changed for hydroxide. in this connection, mechanical treatment of the mixture under the same experimental conditions is unreasonable. The mixture obtained by precipitation from solution without mechanical treatment allows carrying out the synthesis even at 700 °С.