Interstitial oxygen molecules in amorphous SiO2. III. Measurements of dissolution kinetics, diffusion coefficient, and solubility by infrared photoluminescence

Abstract

Concentration changes of interstitial oxygen molecules (O2) in amorphous SiO2(a-SiO2) thermally annealed in oxygen atmosphere were examined by the O2 photoluminescence at 1272 nm excited with 765-nm light of titanium sapphire laser. This highly sensitive technique allows the time- and temperature-dependent concentration changes of interstitial O2 due to their incorporation from an oxygen atmosphere to be directly measured. The data provide the dissolution rate, the diffusion coefficient, and the solubility of interstitial O2 in a-SiO2 and are able to exclude interferences from other forms of mobile oxygen species in a-SiO2. These observations confirm that O2 molecules are incorporated into a-SiO2 without separating into monoatomic species, diffuse in a-SiO2 without extensive interaction with the a-SiO2 network, and play a primary role in the thermal oxidation of silicon.

Diffusion and reactions of interstitial oxygen species in amorphous SiO2: A review

“…The PL technique described in Section 2.1 is sensitive enough to study the dissolution and diffusion of O 2 in aSiO 2 caused by thermal annealing in air [34][35][36]. Fig.…”

Properties of HO 2 • radicals induced by γ-ray irradiation in silica nanoparticles

“…The proportionality factor between the O 2 concentration and the PL intensity I PL just defined is equal to the ratio between α, a quantity assumed independent of the type of nanoparticle considered [18,19], and the PL lifetimes. Taking advantage of this consideration it is possible to define I PLrevised :…”

“…For this latter sample the O 2 loading was done at T = 1000°C for 30 days. The final O 2 concentration was 3.6 · 10 17 cm -3 [19,23].…”

“…We can express the factor K i as the ratio between a quantity α (here considered indipendent from the features of the nanoparticles [17][18][19]22]) and the O 2 PL life time τ i :…”

“…In fact, to detect and evaluate the amount of interstitial O 2 one can make use of the electronic transition in O 2 from the first excited state 1 Δ g to the ground state 3 Σ g − . This transition gives rise to an infrared (IR) photoluminescence (PL) band at~1272 nm that a Raman spectrometer equipped with a Nd:YAG laser source at 1064 nm can detect [8,[16][17][18][19][20].…”