Investigation of interface defects in nanocrystalline SnO2 by positron annihilation

Defect driven ferromagnetism in SnO2: a combined study using density functional theory and positron annihilation spectroscopy

“…In the light of our results, decreasing trend of ferromagnetic moment with high temperature annealing 14,17 of SnO 2 nanoparticles can now be understood in the following way. Above 400 o C annealing grain boundary defects starts to recover and average grain size is increased 17,38 . The situation of nano-SnO 2 38 is very similar to that of nano-ZnO.…”

Characterization of densified fully stabilized nanometric zirconia by positron annihilation spectroscopy

“…In a study using ACAR measurements on CuO compacts, 14 it was reported that an increase in the low-momentum fraction annihilations ͑associated with an increase in the open-volume signal͒ seen in nanometric samples ͑15-90 nm͒ was attributed to positron trapping at grain boundaries. In another study on nanocrystalline SnO 2 compacts by Shek et al, 15 the average positron lifetime decreased with increasing sintering temperature, an observation attributed to the elimination of grain boundaries by grain growth during the sintering process.…”

“…The PAS technique has been used previously for characterizing ceramics, [11][12][13][14][15] including zirconia. [16][17][18][19] The positron annihilation lifetime spectroscopy ͑PALS͒ mode has been the most commonly used, but the angular correlation of the annihilation radiation ͑ACAR͒ and Doppler broadening have been used as well.…”

Microstructural evolution of oxides and semiconductor thin films

“…The first target (abbreviated as Target I) was prepared from pure nanocrystalline SnO 2 powder synthesized with the sol-gel method described in [28]. Meta-stannic acid sol (parent sol) was precipitated by treating a cold ethanol solution of SnCl 4 (27%) with an aqueous ammonia solution (28%) until a suitable pH value was reached.…”