Event 

Title:
Seminarios en el Acelerador - Ionoluminiscencia en silice y cuarzo inducida por irradiación con iones pesados
When:
22.12.2011 - 22.12.2011
Where:
CMAM - Madrid
Categoría:
Seminarios informales en el Acelerador

Description

Ponente: Ovidio Peña Rodríguez

Ionoluminiscencia en silice y cuarzo inducida por irradiación con iones pesados

Abstract:

O. Peña-Rodríguez,(a,b) D. Jiménez-Rey,(a) J. Olivares,(a,b) J. Manzano-Santamaría,(a) A. Muñoz,(a) A. Rivera,(c) and F. Agulló-López(a)

(a) Centro de Microanálisis de Materiales (CMAM), Universidad Autónoma de Madrid (UAM), Cantoblanco, E-28049 Madrid, Spain

(b) Instituto de Óptica, Consejo Superior de Investigaciones Científicas (CSIC), C/Serrano 121, E-28006 Madrid, Spain

(c) I. de Fusión Nuclear, Universidad Politécnica de Madrid, C/ José Abascal 2, E-28006 Madrid, Spain

Ionoluminescence (IL) is a very sensitive technique to investigate radiation-induced defects and processes in dielectric materials. The creation of defects in amorphous as well as crystalline SiO2 has been thoroughly investigated under ionizing and charged-particle irradiation (electrons, light ions) [1–3]. Recently, such investigations have been extended to irradiation with swift heavy ions; i.e., in the regime where electronic stopping power is dominant. In this work we have tried to elucidate the role of excitonic processes (self-trapping and relaxation) on light emission and on defect creation. To this end, the comparison between the IL kinetics of both SiO2 phases, amorphous silica and crystalline quartz, appears quite relevant, since it is expected that the probability of excitons becoming self-trapped in stressed bonds (present in silica or in damaged quartz) is much higher than on unstressed ones (pristine quartz) [4]. The light-emission and defect-creation kinetics and yields have been comparatively analyzed as a function of stopping power, as we have previously discussed [5]. The experiments were performed in the 5 MV tandetron accelerator installed at CMAM [6], the emission spectra induced by irradiation with different elements (B, O, F, Cl and Br) and energies ranging from 3 to 25 MeV. The irradiations cover a broad range of electronic and nuclear stopping powers (Se from around 1 to 7 keV/nm). The role of irradiation fluence on the IL kinetics will be analyzed. Similarly, the possible determination of a threshold stopping power for amorphization of quartz will be discussed as well.

[1]  K. Tanimura, T. Tanaka, N. Itoh, Creation of quasistable lattice defects by electronic excitation in SiO2, Phys. Rev. Lett. 51 (1983) 423-426.

[2]  D.L. Griscom, γ and fission-reactor radiation effects on the visible-range transparency of aluminum-jacketed, all-silica optical fibers, J. Appl. Phys. 80 (1996) 2142-2155.

[3]  L. Skuja, M. Hirano, H. Hosono, K. Kajihara, Defects in oxide glasses, Phys. Stat. Sol. C. 2 (2005) 15-24.

[4]  R.M. Van Ginhoven, H. Jónsson, L.R. Corrales, Characterization of exciton self-trapping in amorphous silica, J. Non-Cryst. Sol. 352 (2006) 2589-2595.

[5]  A. Rivera, A. Méndez, G. García, J. Olivares, J.M. Cabrera, F. Agulló-López, Ion-beam damage and non-radiative exciton decay in LiNbO3, J. Lumin. 128 (2008) 703-707.

[6]  CMAM - Centre for Micro Analysis of Materials, http://www.cmam.uam.es/

Venue

CMAM
Venue:
CMAM   -   Website
Street:
Faraday 3, Campus de Cantoblanco
ZIP:
28049
City:
Madrid
Country:
Country: es

Description

El seminario tendrá lugar en la sala de reuniones del CMAM