SPECIFICATIONS
Technical details
Profile Functions
Siroquant supports Gaussian and Lorentzian (and any mixture of the two) peak shapes using the Pearson VII and Pseudo-Voigt profile functions. The March preferred orientation parameter is also refinable.
Refinable Profile Parameters:
- Phase Rietveld scales
- Line asymmetry
- Preferred orientation
- Line-width parameters, U1, V1, W1 & U2, V2, W2. (Note: Two line-width functions are allowed for each phase)
- Instrument zero
- Pearson M or Pseudo Voigt shape functions
- Unit cell dimensions (a, b, c, alpha, beta, gamma).
Refinements can be performed in several stages with different combinations of varied parameters.An automatic refinement procedure (Auto-prescale) is also available and produces good ball park estimates for most samples as well as a providing a basis for further refinements.
Siroquant contains an absorption/contrast correction which is essential for quantitative phase analysis.
The software uses Bragg-Brentano geometry calibration curves, this is essential where strong low-angle XRD peaks are present. Corrections of 2 x peak height are common at low angles. Siroquant allows Rietveld analysis on minerals without a published crystal structure using a unique program structure featuring observed HKL files. This allows the analysis of poorly crystalline clays.
The program can be used to analyse mixtures of up to 25 minerals. (Cement analysis requires >15 phases). The program includes “Anomalous Dispersion” corrections for the correction of resonance effects in the absorption of x-rays.
Siroquant has a robust least squares refinement scheme. Automatically staged refinement has been recommended by industrial users to allow automatic plant analysis using a sequence of various refinements from a poorly defined starting point. Up to 100 variables can be refined in each cycle.
Siroquant includes a comprehensive technical manual that has been assembled by users and technical experts to provide an easy to follow reference and a strong technical reference guide including a comprehensive list of references.