Screenshots

Normal X-Ray Reflectivity

Dichroic/Magnetic Reflectivity

Magnetic Asymmetry

Slicing of sample

ReMagX is a scientific software to calculate and fit the specular x-ray reflection from a thin film sample taking into account magnetic contributions. It has been developed during the last years at the Max-Planck-Institute for Metal Research in Stuttgart, Germany.

The program is able to simulate standard non-magnetic x-ray reflectivity for variable energies based upon the so called Parratt formalism (see screenshot: Normal X-Ray Reflectivity and reference [1] for more details). However, the real aim and strength of ReMagX is the simulation of the reflectivity from a magnetic multilayer under circular polarized x-rays. By calculating the specular reflection of a transition metal sample, e.g. Co/Cu multilayer, at the L-edge of Co and taking into account variations in the reflectivity based upon the XMCD effect a dichroic reflectometry is available. The Dichroic/Magnetic Reflectivity screenshot shows a calculated reflection from a Co/Cu multilayer with arbitrary chosen magnetization of the Co layers (note the δm and βm values given in the layer input table). Beside the actual dichroic reflectivity curve, the so called asymmetry (weighted difference between R+ and R-) is important since the resulting curve only contains contributions from the asymmetry caused by the XMCD effect in the sample. An exmple of such an asymmetry is shown in the following image: Magnetic Asymmetry.

Motivation

Materials composed of several thin layers, so called multilayers, are of great scientific interest. The reduced dimensionality and/or the existence of many interfaces can lead to novel physical phenomena. Magnetic functional materials and films are of interest for data storage devices such as hard disks, read heads and sensors. To investigate the magnetism in such systems, a techniqe able to probe the local magnetic moments in an element selective way is desirable. X-ray Magnetic Reflectometry is such a technique. By making use of the x-ray magnetic circular dichroism (XMCD) as additional contrast for standard x-ray reflectivity a method is available to probe chemical and magnetic depth profiles of thin films.

Features

• Two different algorithms for reflectivity calculation (Matrix/Parratt)
• Adaptive slicing/layer segmentation module
• Three different methods for optical density calculation
• Processes optical-constant database files for maximum flexibility
• Variable x-ray polarization
• Magnetism on a per-layer base or by introducing artificial moment
• Four different fit routines (Genetic Algorithm, Levenberg-Marquardt, Simplex, Simulated Annealing)
• Data import modul

If you are interested in ReMagX and magnetic reflectivity feel free to contact us:
S. Brück
&
PD Dr. Eberhard Goering