29Si Hyperfine Structure of the E'_αCenter in Amorphous Silicon Dioxide

Buscarino, G.; Agnello, S.; Gelardi, F. M.

29Si Hyperfine Structure of the E'_αCenter in Amorphous Silicon Dioxide

Authors

Buscarino, G.

Agnello, S.

Gelardi, F. M.

Description

We report a study by electron paramagnetic resonance (EPR) on the E'_αpoint defect in amorphous silicon dioxide (a-SiO2). Our experiments were performed on gamma-ray irradiated oxygen-deficient materials and pointed out that the 29Si hyperfine structure of the E'_alpha consists in a pair of lines split by 49 mT. On the basis of the experimental results a microscopic model is proposed for the E'_alpha center, consisting in a hole trapped in an oxygen vacancy with the unpaired electron sp3 orbital pointing away from the vacancy in a back-projected configuration and interacting with an extra oxygen atom of the a-SiO2 matrix.
4 pages