REFLEX: a program for the analysis of specular X-ray and neutron reflectivity data

Abstract

The use of X-ray and neutron reflectivity has been generalized worldwide for scientists who want to determine specific physical properties (such as electrondensity profile, scattering-length density, roughness and thickness) of films less than 200 nm thick deposited on a substrate. This paper describes a freeware program named REFLEX, which is a standalone program dedicated to the simulation and analysis of X-ray and neutron reflectivity from multilayers. This program was first written two decades ago and has been constantly improved since, but never published until now. The latest version of REFLEX covers generalized types of calculation of reflectivity curves including both neutron and X-ray reflectivity. In the case of X-rays, the program can deal with both s and p polarization, which is quite important in the soft X-ray region where the two polarizations can yield different results. Neutron reflectivity is calculated within the framework of non-spin-polarized neutrons. REFLEX has also been designed to include any type of fluid (such as supercritical CO 2 ) on top of the analysed film and includes corrections of the footprint effect for analysis on an absolute scale. computer programs J. Appl. Cryst. (2019). 52, 201-213 Vignaud and Gibaud REFLEX 203Figure 1Illustration of the plane of incidence for a stratified medium. The signs + and À indicate the direction of propagation of the wave.

High-temperature X-ray scattering studies of atomic layer deposited IrO2

“…The MAUD software package research papers was used for Rietveld refinement of the diffractograms (Lutterotti et al, 2004). Fitting to the XRR data was done using REFLEX35 (Vignaud & Gibaud, 2019) and MOTOFIT (Nelson, 2006), and on a few occasions STOCHFIT was used to evaluate the structure (Danauskas et al, 2008).…”

Investigation of the initial deposition steps and the interfacial layer of Atomic Layer Deposited (ALD) Al2O3 on Si

“…All measurements were carried out in θ −θ geometry for which the sample was kept fixed during the measurements. Experimental curves were fitted using reflex software [37] based on the Parratt algorithm to obtain the thickness and the electron density profile of the prepared layer.…”

“…The ALD films using various numbers of cycles were characterized by XRR in order to determine their thickness. The XRR data were fitted using a matrix model (Parratt formalism [37]) by considering a fixed density of Al2O3 in the deposited layer in order to recover its thickness. XRR data and calculated curves are shown in Fig.…”

Structure and Elastic Properties of an Unsymmetrical Bi-Heterocyclic Azo Compound in the Langmuir Monolayer and Langmuir–Blodgett Film

“…46 , 47 Analysis of XRR data has been carried out using the matrix technique. 46 , 48 In general, the electron-density variation in a specimen is determined by assuming a model and comparing the simulated profile with the experimental data. EDP is extracted from the fitting of experimental XRR data.…”