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Modeling and Optimization Algorithm to Analyse Xrpd Data Via Modulation and Pseudo-Voigt Functions

Published online by Cambridge University Press:  06 March 2019

Giovanni Berti
Giovanni Berti*
Affiliation:
University of Pisa - Italy Dept. of Earth Sciences Via S. Maria 53 -156126 - Pisa, Italy e-mail: berti@dst.unipi.it
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Abstract

The composition of the sample related-effects with those from the instrument, has been carried out by convolution of involved terms. The sample-related effects have been modelled via the modulation function accounting for packed parallel planes, named here “layers”, and other structure-related parameters. The instrumental parameters have been determined using DISVAR93, a softawre package allowing the diffraction profiles to be represented in the more convenient shape of a pseudo-Voigt function. A constrained optimization process is the basis for determining these instrumental parameters; their calibration is typically carried out by adopting an external standard sample. The comparison of the modeled intensity distribution with the experimental one is performed via minimization of χ2 where the convolutor and minimizator are embedded engines of the algorithm.

Type
Research Article
Information
Advances in X-Ray Analysis , Volume 39: Forty-Fourth Annual Conference on Applications of X-ray Analysis, July 31 - August 4, 1995 , 1995 , pp. 465 - 471
Copyright
Copyright © International Centre for Diffraction Data 1995

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