Synthesis of nanophase TiO2 by ion beam sputtering and cold condensation technique

Nanoparticles of TiO2 have been synthesized by an ion beam sputtering-cold condensation (IBS-CC) technique. A sintered TiO2 was sputtered by an ion be am (Kaufman source, 900 eV, Ar+ ions) and the ejected atoms/radicals were m ade to condense on a Si(100) substrate herd at -50 degrees C. X-ray diffrac tion data showed that the average particle size in the as-deposited materia l is about 3.5 +/- 1.5 nn. Upon annealing at 600 degrees C for five hours, the average particle size was seen to increase to about 70 +/- 10 nm. Furth er annealing for one hour at 900 degrees C led to increase of average parti cle size to 200 +/- 20 nm. X-ray spectroscopy, Raman spectroscopy and photo luminescence data have been used to reveal the presence and relative concen trations of rutile and anatase phases of TiO2 in the as-deposited and annea led samples. The IBS-CC method is found to yield a more compact particle si ze distribution as compared to the method based on Laser Ablation.