Open AccessX‐ray reflectivity from curved liquid interfaces
Author(s) -
Festersen Sven,
Hrkac Stjepan B.,
Koops Christian T.,
Runge Benjamin,
Dane Thomas,
Murphy Bridget M.,
Magnussen Olaf M.
Publication year - 2018
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577517018057
Subject(s) - reflectivity , optics , curvature , materials science , layering , drop (telecommunication) , reflection (computer programming) , x ray reflectivity , beam (structure) , laser , physics , geometry , telecommunications , botany , mathematics , computer science , biology , programming language
X‐ray reflectivity studies of the structure of liquid–vapour and liquid–liquid interfaces at modern sources, such as free‐electron lasers, are currently impeded by the lack of dedicated liquid surface diffractometers. It is shown that this obstacle can be overcome by an alternative experimental approach that uses the natural curvature of a liquid drop for variation of the angle of incidence. Two modes of operation are shown: (i) sequential reflectivity measurements by a nanometre beam and (ii) parallel acquisition of large ranges of a reflectivity curve by micrometre beams. The feasibility of the two methods is demonstrated by studies of the Hg/vapour, H 2 O/vapour and Hg/0.1 M NaF interface. The obtained reflectivity curves match the data obtained by conventional techniques up to 5α c in micro‐beam mode and up to 35α c in nano‐beam mode, allowing observation of the Hg layering peak.