The desorption spectrum of N¹⁸O adsorbed on the surface of SrTiO₃ powder was determined by Temperature Programmed Desorption (TPD). The changes of desorption amount were discussed. The results indicate that the mass of N¹⁶O desorption is followed with N¹⁸O of adsorption on SrTiO₃. Otherwise a small amount of N₂, N¹⁸O and N₂¹⁶O also desorbed from the particle surface. N¹⁶O formed due to the exchange of oxygen isotopes and escaped from the surface of SrTiO₃ particles during heating the particles pretreated with the absorption of N¹⁸O gas. With increasing the exposure amount of N¹⁸O gas, the desorption amount of N¹⁶O increased and the peak desorption temperature decreased. However, the desorption amount of N¹⁶O tended to become constant when the surface coverage of N¹⁸O gas was higher than a certain value.

Key words: N¹⁸O, adsorption, SrTiO₃, TPD