Pattern

 

The sub-menu Pattern is shown on the left. It includes the following options:

 

·       2-Theta Range

·        Single

·        Background

 

 

 

2-Theta Range

Allows to modify the 2-theta pattern range specified as input data. 

The option is active only when the following message:

Press “Pattern > 2-Theta Range” to modify 2-theta range or “Continue” to go on

is displayed at the bottom of the window. A new window (shown in Fig. 4.1) is open:

 

 

Fig. 4.1

 

 the current values of  Two-Theta min and Two-Theta max are displayed on the top of the window and two vertical lines mark their positions on the plot. The values can be changed by typing the new ones or by moving the lines; in this case move the cursor on the line, click on the left mouse button and drag it in the wanted direction at the desired position.

 

Zoom In / Zoom Out options are available during the operation. Click OK to confirm the modification or Cancel to leave the menu without any change.

 

WARNING! After confirming the 2-theta pattern modification, it is no more possible to come back to the previous angular range; it can be recovered only by re-loading the input file.

 

 

 

Single

Allows to modify the Single Peak or Reference Range automatically selected by the program.

The option is active only when the following message :

Press “Pattern > Single” to modify single peaks  or “Continue” to go on

is displayed at the bottom of the window. The new window shown in Fig. 4.2 is open;

 

Fig. 4.2

 

Horizontal lines mark the interval range of each phase on the plot; for the selected phase (by default it is the first one, according to the order specified in the input file) the starting and final 2-theta values of the single peak range are displayed on the top of the window as well as the corresponding phase number (Single # n); two vertical lines mark on the plot the current interval. Click on the arrows at the right of "Single #" to select the peak to modify; the interval limits can be changed by typing the new values or by moving the vertical lines; in this case move the cursor on the line, click on the left mouse button and drag it in the wanted direction at the desired position.

 

Zoom In / Zoom Out options are available during the operation. Click OK to confirm the operation and, subsequently, click on Continue of the Main Menu to carry out the automatic fit of the new peak ; click Cancel to leave the sub-menu without any change.

 

 

 

Background

 

Allows to modify the background model automatically defined by the program.

The option is active only when the following message :

Press “Pattern > Background” to modify default  or “Continue” to go on

is displayed at the bottom of the window. The new window shown in Fig. 4.3 is open; 

 

 

Fig. 4.3

 

the background line is plotted as well as the points located by the program and used for the automatic definition of the model. To change it some options are available at the bottom of the window:

 

· Zoom: to have a zoom of a selected area of the whole pattern

· Function (see Fig. 4.3.1): to modify the function and the number of coefficients (for Polynomial and Chebyshev)

 

 

Fig. 4.3.1

 

· Add: to add points. Move the cursor on the wanted position and click on the left mouse button, then click OK to confirm or Cancel to come back to the calling menu without any change.

WARNING! If you are working on a zoomed area and some points have been added, the horizontal scroll-bar of the Zoom option becomes non active until you click on OK or Cancel.

 

· Delete: to delete points. Move the cursor on the point to delete and click on the left mouse button, then click OK to confirm or Cancel to come back to the calling menu without any change.

WARNING! If you are working on a zoomed area and some points have been deleted, the horizontal scroll-bar of the Zoom option becomes non active until you click on OK or Cancel.

 

· Apply: to apply the user’s modifications; the new background will be plotted.

 

WARNING! If the set of points has been modified (Add/Delete) before clicking on Apply, the automatic procedure is carried out and the number of coefficients for the selected function is automatically supplied; to apply the user’s value is necessary an additional operation.

The default function is the Young’s polynomial; to change it (before the first automatic background calculation) click on Parameters > Global when the following message

 

 Press “Parameters” to supply your starting value  or “Continue” to go on

is displayed at the bottom of the window, or supply the suitable "data directive" in the input file.