Tools

The sub-menu  Tools is shown on the left.

It includes graphical (Plot Options, Info, Presentation) and computational (Find P.O. and Le Bail) options.

 

The sub-menu becomes available when the following message

 

Press "Parameters" to supply your starting value or "Continue" to go on

 

is displayed at the bottom of the window.

 

 

 

 

 

Plot Options

 

The Plot Options allow to select the datasets to plot on the screen by means of the General and Phases folders.

 

 General folder  includes: observed and calculated patterns, background line and Background Points, difference profile, X axis, reflections marks, Single or Reference range marks (see Fig. 3.1.1). The X scale can be choosen between "Two-Theta" and "d" values.

 

 

 

 

 

 

 Fig. 3.1.1

 

 

 Phases folder (see Fig. 3.1.2): for the selected phases it allows to choose between  the calculated profile (available not before the Rietveld Procedure) and the relative Intensity (plotted as a vertical bar) of each reflection. Examples of the two kind of plot are shown in Fig. 3.1.3 and 3.1.4.

 

 

 

 

 

 

Fig. 3.1.2

 

 

 

 

 

Fig. 3.1.3

 

 

 

 

 

 

Fig. 3.1.4

 

 

 

Info

 

The Info sub-menu (on the left) allows to have information about:

 

· the reflections (HKL)

· the Full Width at Half Maximum (FWHM)

· the Mixing Parameters (Mixing Par.)

 

 

 

 

 HKL 

 

The window shown in Fig. 3.2.1 is open. Clicking on any position by using the left mouse button,the following  information will be displayed: "Two Theta", "d" and "counts" values corresponding to the clicked point, on the Top; on the Bottom, Miller indices, 2-theta value and corresponding phase of each reflection included into an interval  1.0 degree wide and centred on the clicked point.

 

 

 Fig. 3.2.1

 

Click on ">>" and "<<"  buttons to scroll the list; click on Cancel to leave the sub-menu.

 

 

FWHM 

 

For a selected phase the Full Width at Half Maximum trend versus 2-theta is plotted  (Fig. 3.2.2)

 

 

Fig. 3.2.2

 

Mixing Par.  

 

When the Pearson VII or the Pseudo-Voigt functions have been adopted to describe the profile shape of peaks, for a selected phase the Mixing Parameter trend versus 2-theta is plotted (Fig. 3.2.3);

 

 

 Fig. 3.2.2 

  

 

 

Presentation

 

The Presentation sub-menu (on the left) allows to define:

 

 

 

 

 

           

 

 

 

 

 

 

 

 

Find P.O.

The  Find P.O. option allows to run an automatic procedure aiming at  processing the selected phase in order to find possible directions of preferred orientation (for cylindrical symmetry samples). The candidate planes will be displayed on the screen ordered as the increasing value of the corresponding preferred orientation G parameter of the March-Dollase function  (see Fig. 3.3.1 ). The user can eventually supply this information to the program by means of the Parameters dialog-box.

 

 

  Fig. 3.3.1

 

Le Bail

This option (see Fig. 3.4.1) allows to extract the integrated intensity of each reflection of a selected phase by means of the Le Bail algorithm. The corresponding .pha file must be supplied to the program, including cell parameters and space group; atomic coordinates should be supplied if a structural model is known for the phase (even if partial or not properly correct for single intensities), otherwise only one atom in random position is required to start the procedure.

 

 

 Fig. 3.4.1

The option is available at different stages of the run:

1) when the message

Press "Parameters" to supply your starting value or "Continue" to go on

is displayed at the bottom of the window; at this stage the algorithm will be applied in the single peak refinement of the Preliminary procedure and in the subsequent Rietveld refinement, after each l.s.q. cycle;

2) when the message

Press "Refinement" to set your own strategy or "Continue" to go on

is displayed at the bottom of the window and the initial calculated pattern is plotted; at this stage the algorithm will be applied in the subsequent Rietveld refinement, after each l.s.q. cycle;

3) when the message

Press "Refinement" to set your own strategy or "Exit" to stop

is displayed at the bottom of the window and the final pattern is plotted; at this stage, after selecting the option, click on Continue button of the Main Menu to apply the Le Bail calculation and to plot the updated pattern; the algorithm will keep active in all the subsequent operations.