TY - JOUR
T1 - Polyamorphic transformation induced by electron irradiation in a-SiO2 glass
AU - Buscarino, Gianpiero
AU - Gelardi, Franco Mario
AU - Boscaino, Roberto
AU - Agnello, Simonpietro
PY - 2009
Y1 - 2009
N2 - We report a study by electron paramagnetic resonance of amorphous silicon dioxide (a-SiO2) irradiated by 2.5 MeV electrons in the dose range from 1.2×103 to 5×106 kGy. By measuring the change in the splitting of the primary 29Si hyperfine doublet of the E centers we evidenced an irradiation induced local (around the defects) densification of a-SiO2. Our data show that the local degree of densification of the materials is significantly higher than that obtained by mean density measurements, suggesting that the structural modifications induced by electron irradiation take place prevalently within confined defective regions of the material. The overall results we have found have permitted us to obtain a detailed quantitative description of the electron irradiation-induced densification process of a-SiO2 and to point out relevant physical properties which have for many years remained elusive. Among them, we have found strong evidences that the processes of permanent densification induced by irradiation or by high hydrostatic pressure involve quite similar structural modification of the a-SiO2 matrix.
AB - We report a study by electron paramagnetic resonance of amorphous silicon dioxide (a-SiO2) irradiated by 2.5 MeV electrons in the dose range from 1.2×103 to 5×106 kGy. By measuring the change in the splitting of the primary 29Si hyperfine doublet of the E centers we evidenced an irradiation induced local (around the defects) densification of a-SiO2. Our data show that the local degree of densification of the materials is significantly higher than that obtained by mean density measurements, suggesting that the structural modifications induced by electron irradiation take place prevalently within confined defective regions of the material. The overall results we have found have permitted us to obtain a detailed quantitative description of the electron irradiation-induced densification process of a-SiO2 and to point out relevant physical properties which have for many years remained elusive. Among them, we have found strong evidences that the processes of permanent densification induced by irradiation or by high hydrostatic pressure involve quite similar structural modification of the a-SiO2 matrix.
KW - densification
KW - electron beam effects
KW - glass
KW - hyperfine interactions
KW - paramagnetic resonance
KW - polymorphic transformations
KW - densification
KW - electron beam effects
KW - glass
KW - hyperfine interactions
KW - paramagnetic resonance
KW - polymorphic transformations
UR - http://hdl.handle.net/10447/39337
M3 - Article
VL - 2009-09-25
JO - PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS
JF - PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS
SN - 1098-0121
ER -