Früh, J.; Rühm, A.; Möhwald, H.; Krastev, R.; Köhler, R.: Reflectometry on curved interfaces. Physica B 457 (2015), p. 202-211
Reﬂectometry is known since long as an interferometric method which can be used to characterize surfaces and thin ﬁlms regarding their structure and, to a certain degree, composition as well. Properties like layer structures, layer thickness, density, and interface roughness can be determined by ﬁtting the obtained reﬂectivity data with an appropriate model using a recursive ﬁtting routine. However, one major drawback of the reﬂectometric method is its restriction to planar surfaces. In this article we demonstrate an approach to apply X-ray and neutron reﬂectometry to curved surfaces bymeans of the example of bent bare and coated glass slides. We prove the possibility to observe all features like Fresnel decay, Kiessig fringes, Bragg peaks and off-specular scattering and are able to interpret the data using common ﬁtting software and to derive quantitative results about roughness, layer thickness and internal structure.The proposed method has become practical due to the availability of high quality 2D-detectors. It opens up the option to explore many kinds and shapes of samples, which, due to their geometry, have not been in the focus of reﬂectometry techniques until now.