Thermal Oxidation of Nanosized Tantalum Diboride.

We investigated the morphology and phase composition of tantalum diboride (TaB2) oxidation products by oxygen in the air across a temperature range of 20 to 1000°C. At isothermal conditions of 450, 500, 550, and 600°C, we determined the oxidation rate constants for TaB2 nanoparticles with an average particle diameter of ~70 nm (0.0006, 0.0027, 0.009, and 0.015 s–1, respectively). The apparent activation energy for the oxidation reaction of TaB2 nanoparticles, derived from the temperature dependence of the rate constants, was estimated to be 115 ± 6 kJ/mol. [ABSTRACT FROM AUTHOR]