Non-stiochiometric SnO~2~-~x nanocrystalline material were successfully prepared through Sol-Gel process using anhydrous stannic chloride and iso-propyl alcohol. TEM observation shows that the mean diameter of the powder sintered at 700℃ for 2 hours is about 20nm. By the investigation of XRD and ESR, we can conclude that the sample sintered at 300℃ for 2 hours was amorphous and it grew into nanocrystalline will the oxygen vacancies and defects when sintered at 700℃ for 2 hours. Using these conclusion, the ESR signals and the difference between the two SnO~2~-~x samples are explained.

Key words: PARAMAGNETIC RESONANCE, X-RAY PHOTOELECTRON SPECTROMETRY, STOICHIOMETRY