Method for characterizing self-assembled monolayers as antirelaxation wall coatings for alkali vapor cells

Published

July 30, 2008

Author(s)

Y Yi, Hugh Robinson, Svenja A. Knappe, J Maclennan, C Jones, Chengjie Zhu, N Clark, John E. Kitching

Abstract

A method for characterizing self-assembled monolayers (SAMs) in terms of their performance as anti-relaxation wall coatings for alkali atom vapor cells is described. A combination of initial surface analysis with subsequent laser spectroscopy is used to give insight into the quality of the coating as well as its performance under the exposure to alkalis as occurs, for example when coatings are used in applications like atomic magnetometers or clocks. Fused silica plates coated with octadecyltrichlorosilane (OTS) SAMs were used to make cubic 87Rb gas cells. The surfaces were characterized using X-ray diffraction, contact angle measurements, and atomic force microscopy (AFM). Measurements of hyperfine resonance line widths and frequency shifts show that the rubidium vapor atoms collide up to 40 times with the walls of the cells before their coherence relaxes and their adsorption energy is around 0.065(2) eV. Chemical analysis of the cell indicates some weak reactions between the coating and the rubidium atoms.

Citation

Journal of Applied Physics

Volume

104

Issue

023534

Pub Type

Journals

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Keywords

alkali atom vapor cells, anti-relaxation wall coatings, octadecyltrichlorosilane, OTS, SAM, self-assembled monolayers

Citation

Yi, Y. , Robinson, H. , Knappe, S. , Maclennan, J. , Jones, C. , Zhu, C. , Clark, N. and Kitching, J. (2008), Method for characterizing self-assembled monolayers as antirelaxation wall coatings for alkali vapor cells, Journal of Applied Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50615 (Accessed March 13, 2025)