Electron paramagnetic resonance (EPR) data on X-ray irradiated Ge:Sn codoped SiO2 samples (0.1, 0.5, 1 wt% Sn and 1 or 3 wt% Ge) produced by sol-gel method are presented. Radiation-induced Ge and Sn related EPR signals are observed due to Ge- and Sn- E' centers, i.e. unpaired electrons in sp(3) orbital of three-fold coordinated Ge or Sn sites. The E' center creation yield is analyzed in samples with different Sn/Ge doping ratio. The concentrations of the two EPR species are not proportional to the dopant contents, the creation of Sn-E' centers being favored with respect to Ge-E'. Lower Ge-E' creation yield is observed in samples with higher Sn content at fixed Ge doping. A simple kinetic model shows that the competitive mechanism of Sn-E' creation cannot fully justify the data if the creation of Ge- and Sn-E' is supposed to be independent, as expected from randomly distributed non-interacting dopant species. Ge and Sn sites are thus proposed to be preferentially spatially related. (C) 1999 Elsevier Science Ltd. All rights reserved.
Chiodini, N., Meinardi, F., Morazzoni, F., Paleari, A., Scotti, R., Spinolo, G. (1999). Electron paramagnetic resonance study of Ge and Sn doping of SiO2 from sol-gel method. SOLID STATE COMMUNICATIONS, 112(10), 565-568 [10.1016/S0038-1098(99)00393-2].
Electron paramagnetic resonance study of Ge and Sn doping of SiO2 from sol-gel method
CHIODINI, NORBERTO;MEINARDI, FRANCESCO;MORAZZONI, FRANCA;PALEARI, ALBERTO MARIA FELICE;SCOTTI, ROBERTO;SPINOLO, GIORGIO MARIO
1999
Abstract
Electron paramagnetic resonance (EPR) data on X-ray irradiated Ge:Sn codoped SiO2 samples (0.1, 0.5, 1 wt% Sn and 1 or 3 wt% Ge) produced by sol-gel method are presented. Radiation-induced Ge and Sn related EPR signals are observed due to Ge- and Sn- E' centers, i.e. unpaired electrons in sp(3) orbital of three-fold coordinated Ge or Sn sites. The E' center creation yield is analyzed in samples with different Sn/Ge doping ratio. The concentrations of the two EPR species are not proportional to the dopant contents, the creation of Sn-E' centers being favored with respect to Ge-E'. Lower Ge-E' creation yield is observed in samples with higher Sn content at fixed Ge doping. A simple kinetic model shows that the competitive mechanism of Sn-E' creation cannot fully justify the data if the creation of Ge- and Sn-E' is supposed to be independent, as expected from randomly distributed non-interacting dopant species. Ge and Sn sites are thus proposed to be preferentially spatially related. (C) 1999 Elsevier Science Ltd. All rights reserved.
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