Magnetic contrast layers with functional SiO2 coatings for soft-matter studies with polarized neutron reflectometry
(2024) In Journal of Applied Crystallography 57(Pt 4). p.1145-1153- Abstract
This study introduces silicon substrates with a switchable magnetic contrast layer (MCL) for polarized neutron reflectometry (PNR) experiments at the solid–liquid interface to study soft-matter surface layers. During standard neutron reflectometry (NR) experiments on soft-matter samples, structural and compositional information is obtained by collecting experimental data with different isotopic contrasts on the same sample. This approach is normally referred to as contrast matching, and it can be achieved by using solvents with different isotopic contrast, e.g. different H2O/D2O ratios, and/or by selective deuteration of the molecules. However, some soft-matter systems might be perturbed by this approach, or it... (More)
This study introduces silicon substrates with a switchable magnetic contrast layer (MCL) for polarized neutron reflectometry (PNR) experiments at the solid–liquid interface to study soft-matter surface layers. During standard neutron reflectometry (NR) experiments on soft-matter samples, structural and compositional information is obtained by collecting experimental data with different isotopic contrasts on the same sample. This approach is normally referred to as contrast matching, and it can be achieved by using solvents with different isotopic contrast, e.g. different H2O/D2O ratios, and/or by selective deuteration of the molecules. However, some soft-matter systems might be perturbed by this approach, or it might be difficult to implement, particularly in the case of biological samples. In these scenarios, solid substrates with an MCL are an appealing alternative, as the magnetic contrast with the substrate can be used for partial recovery of information on the sample structure. More specifically, in this study, a magnetically soft Fe layer coated with SiO2 was produced by ion-beam sputter deposition on silicon substrates of different sizes. The structure was evaluated using X-ray reflectometry, atomic force microscopy, vibrating sample magnetometry and PNR. The collected data showed the high quality and repeatability of the MCL parameters, regardless of the substrate size or the thickness of the capping SiO2 layer. Previously proposed substrates with an iron MCL used an Au capping layer. The SiO2 capping layer proposed here allows reproduction of the typical surface of a standard silicon substrate used for NR experiments and is compatible with a large variety of soft-matter samples. This application is demonstrated with ready-to-use 50 x 50 x 10 mm substrates in PNR experiments for the characterization of a lipid bilayer in a single solvent contrast. Overall, the article highlights the potential of PNR with an MCL for the investigation of soft-matter samples.
(Less)
- author
- Dikaia, Olga ; Luchini, Alessandra ; Nylander, Tommy LU ; Grunin, Alexei ; Vorobiev, Alexei and Goikhman, A.
- organization
- publishing date
- 2024-08
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- ion-beam sputter deposition, iron, magnetic contrast layers, polarized neutron reflectometry, silicon oxide, thin films
- in
- Journal of Applied Crystallography
- volume
- 57
- issue
- Pt 4
- pages
- 9 pages
- publisher
- International Union of Crystallography
- external identifiers
-
- scopus:85200641211
- ISSN
- 0021-8898
- DOI
- 10.1107/S1600576724005387
- language
- English
- LU publication?
- yes
- id
- 8988c1fc-c472-43a2-9e26-c1de5d443a9e
- date added to LUP
- 2024-09-09 14:55:12
- date last changed
- 2024-09-09 14:56:23
@article{8988c1fc-c472-43a2-9e26-c1de5d443a9e,
abstract = {{<p>This study introduces silicon substrates with a switchable magnetic contrast layer (MCL) for polarized neutron reflectometry (PNR) experiments at the solid–liquid interface to study soft-matter surface layers. During standard neutron reflectometry (NR) experiments on soft-matter samples, structural and compositional information is obtained by collecting experimental data with different isotopic contrasts on the same sample. This approach is normally referred to as contrast matching, and it can be achieved by using solvents with different isotopic contrast, e.g. different H<sub>2</sub>O/D<sub>2</sub>O ratios, and/or by selective deuteration of the molecules. However, some soft-matter systems might be perturbed by this approach, or it might be difficult to implement, particularly in the case of biological samples. In these scenarios, solid substrates with an MCL are an appealing alternative, as the magnetic contrast with the substrate can be used for partial recovery of information on the sample structure. More specifically, in this study, a magnetically soft Fe layer coated with SiO<sub>2</sub> was produced by ion-beam sputter deposition on silicon substrates of different sizes. The structure was evaluated using X-ray reflectometry, atomic force microscopy, vibrating sample magnetometry and PNR. The collected data showed the high quality and repeatability of the MCL parameters, regardless of the substrate size or the thickness of the capping SiO<sub>2</sub> layer. Previously proposed substrates with an iron MCL used an Au capping layer. The SiO<sub>2</sub> capping layer proposed here allows reproduction of the typical surface of a standard silicon substrate used for NR experiments and is compatible with a large variety of soft-matter samples. This application is demonstrated with ready-to-use 50 x 50 x 10 mm substrates in PNR experiments for the characterization of a lipid bilayer in a single solvent contrast. Overall, the article highlights the potential of PNR with an MCL for the investigation of soft-matter samples.</p>}},
author = {{Dikaia, Olga and Luchini, Alessandra and Nylander, Tommy and Grunin, Alexei and Vorobiev, Alexei and Goikhman, A.}},
issn = {{0021-8898}},
keywords = {{ion-beam sputter deposition; iron; magnetic contrast layers; polarized neutron reflectometry; silicon oxide; thin films}},
language = {{eng}},
number = {{Pt 4}},
pages = {{1145--1153}},
publisher = {{International Union of Crystallography}},
series = {{Journal of Applied Crystallography}},
title = {{Magnetic contrast layers with functional SiO<sub>2</sub> coatings for soft-matter studies with polarized neutron reflectometry}},
url = {{http://dx.doi.org/10.1107/S1600576724005387}},
doi = {{10.1107/S1600576724005387}},
volume = {{57}},
year = {{2024}},
}