Stability of lithium fluoride thin films as a function of humidity and temperature

Tanner D. Rydalch; Devin M. Lewis; David D. Allred

doi:10.1117/12.2630514

29 August 2022 Stability of lithium fluoride thin films as a function of humidity and temperature

Tanner D. Rydalch, Devin M. Lewis, David D. Allred

Proceedings Volume 12188, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation V; 121884M (2022) https://doi.org/10.1117/12.2630514
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Conference Poster

Abstract

Aluminum mirrors protected by metal fluoride overcoats are crucial for FUV observations. Many contemplated missions specify optics elements with high reflectance down to 103 nm (Lyman beta). Lithium fluoride (LiF) has the highest band gap of any solid material and thus finds applications in FUV optics. However, LiF is difficult to work with because of its hygroscopic nature. The instability of these films was investigated by evaporating LiF onto silicon wafers and aging in environments with different relative humidities and temperatures. Samples were characterized using variable-angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM). From these methods we found that storing LiF in a hot environment improved sample surface stability, and that in dry, hot environments, surfaces became more smooth after many hours in storage.

Conference Presentation

Citation Download Citation

Tanner D. Rydalch, Devin M. Lewis, and David D. Allred "Stability of lithium fluoride thin films as a function of humidity and temperature", Proc. SPIE 12188, Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation V, 121884M (29 August 2022); https://doi.org/10.1117/12.2630514

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available