GenX: an extensible X-ray reflectivity refinement program utilizing differential evolution

GenX is a versatile program using the differential evolution algorithm for fitting X-ray and neutron reflectivity data. It utilizes the Parratt recursion formula for simulating specular reflectivity. The program is easily extensible, allowing users to incorporate their own models into the program. This can be useful for fitting data from other scattering experiments, or for any other minimization problem which has a large number of input parameters and/or contains many local minima, where the differential evolution algorithm is suitable. In addition, GenX manages to fit an arbitrary number of data sets simultaneously. The program is released under the GNU General Public License.

[1]  Press,et al.  X-ray diffraction from Si/Ge layers: Diffuse scattering in the region of total external reflection. , 1995, Physical review. B, Condensed matter.

[2]  B. Tanner,et al.  Analysis of grazing incidence X-ray diffuse scatter from Co–Cu multilayers , 1998 .

[3]  Kao,et al.  Microscopic structure of interfaces in Si1-xGex/Si heterostructures and superlattices studied by x-ray scattering and fluorescence yield. , 1993, Physical review. B, Condensed matter.

[4]  Cheng Dong,et al.  GENEFP: a full-profile fitting program for X-ray powder patterns using the genetic algorithm , 2006 .

[5]  B. L. Henke,et al.  X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E = 50-30,000 eV, Z = 1-92 , 1993 .

[6]  Bland,et al.  Polarized neutron reflection as a probe of magnetic films and multilayers. , 1992, Physical review. B, Condensed matter.

[7]  Rainer Storn,et al.  Differential Evolution – A Simple and Efficient Heuristic for global Optimization over Continuous Spaces , 1997, J. Glob. Optim..

[8]  K. Omote,et al.  The genetic algorithm: refinement of X-ray reflectivity data from multilayers and thin films , 2000 .

[9]  R. Hey,et al.  Grazing-incidence x-ray scattering from stepped interfaces in AlAs/GaAs superlattices , 1997 .

[10]  D. D. de Boer,et al.  Glancing-incidence x-ray fluorescence of layered materials , 1991 .

[11]  G. Vignaud,et al.  The correction of geometrical factors in the analysis of X-ray reflectivity , 1993 .

[12]  David L. Windt,et al.  IMD—software for modeling the optical properties of multilayer films , 1998 .

[13]  C. Zlotea,et al.  Structure of Fe–Co/Pt(001) superlattices: a realization of tetragonal Fe–Co alloys , 2007 .

[14]  E. Politsch,et al.  Unbiased analysis of neutron and X-ray reflectivity data by an evolution strategy , 2002 .