The influences of oxygen impurity contained in nitrogen gas on the annealing of titanium nitride

Commercially available pure nitrogen gas often possesses a small amount of oxygen impurity that may react with many materials at high temperature. In this research the influences of the oxygen impurity contained in the nitrogen gas on the annealing of a nitride model system- titanium nitride pellets were investigated in the temperature range 400-1200 degreesC. Analyzing the in-situ oxygen partial pressure changes when titanium nitride samples were placed in a gas-tight furnace during annealing gives that the dissolution of oxygen in TiN is exothermic and the solubility decreases with increasing temperature. The oxidation involves simultaneously the dissolution of oxygen and the oxide scale formation. X-ray diffraction results show that TiO2 rutile phase is present above 700 degreesC. Changes in the relative integrated intensity and in the morphology after annealing have also been discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.