Refractive index changes in amorphous SiO2 (silica) by swift ion irradiation

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:277

Article

Pena-Rodriguez, O.^1,2  Manzano-Santamaria, J.^1,3  Olivares, J.^1,2  Rivera, A.⁴  Agullo-Lopez, F.¹ 

[1] Univ Autonoma Madrid CMAM UAM, Ctr Microanal Mat, E-28049 Madrid, Spain

[2] Consejo Super Invest Cient IO CSIC, Inst Opt, E-28006 Madrid, Spain

[3] Euratom CIEMAT Fus Assoc, Madrid, Spain

[4] Univ Politecn Madrid, Inst Fus Nucl, E-28006 Madrid, Spain

关键词: Ion irradiation;    Ion damage;    Swift heavy ions;    Silica;    Spectroscopic ellipsometry;   

DOI  :  10.1016/j.nimb.2011.12.057

来源: Elsevier

【 摘 要 】

The refractive index changes induced by swift ion-beam irradiation in silica have been measured either by spectroscopic ellipsometry or through the effective indices of the optical modes propagating through the irradiated structure. The optical response has been analyzed by considering an effective homogeneous medium to simulate the nanostructured irradiated system consisting of cylindrical tracks, associated to the ion impacts, embedded into a virgin material. The role of both, irradiation fluence and stopping power, has been investigated. Above a certain electronic stopping power threshold (similar to 2.5 keV/nm), every ion impact creates an axial region around the trajectory with a fixed refractive index (around n = 1.475) corresponding to a certain structural phase that is independent of stopping power. The results have been compared with previous data measured by means of infrared spectroscopy and small-angle X-ray scattering; possible mechanisms and theoretical models are discussed. (C) 2011 Elsevier B.V. All rights reserved.

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