Optical and microstructural properties of MgF2 UV coatings grown by ion beam sputtering process


Autoria(s): Quesnel, Etienne; Dumas, L.; Jacob, D.; Peiró Martínez, Francisca
Contribuinte(s)

Universitat de Barcelona

Resumo

The optical, mechanical, and microstructural properties of MgF2 single layers grown by ion beam sputtering have been investigated by spectrophotometric measurements, film stress characterization, x-ray photoelectron spectroscopy (XPS), x-ray diffraction, and transmission electron microscopy. The deposition conditions, using fluorine reactive gas or not, have been found to greatly influence the optical absorption and the stress of the films as well as their microstructure. The layers grown with fluorine compensation exhibit a regular columnar microstructure and an UV-optical absorption which can be very low, either as deposited or after thermal annealings at very low temperatures. On the contrary, layers grown without fluorine compensation exhibit a less regular microstructure and a high ultraviolet absorption which is particularly hard to cure. On the basis of calculations, it is shown that F centers are responsible for this absorption, whereas all the films were found to be stoichiometric, in the limit of the XPS sensitivity. On the basis of external data taken from literature, our experimental curves are analyzed, so we propose possible diffusion mechanisms which could explain the behaviors of the coatings.

Identificador

http://hdl.handle.net/2445/25050

Idioma(s)

eng

Publicador

American Institute of Physics

Direitos

(c) American Institute of Physics 2000

info:eu-repo/semantics/openAccess

Palavras-Chave #Propietats òptiques #Revestiments #Microscòpia electrònica #Fluorurs #Pel·lícules fines #Làsers #Optical properties #Coatings #Electron microscopy #Fluorides #Thin films #Lasers
Tipo

info:eu-repo/semantics/article