maud指导手册

maud指导手册内容摘要：

ck the ey e icon to edit. Starting up Maud39。 s Dataset Window In the dataset window, select the Datafiles tab to load the data. Click on Browse and select the esg f ile y ou created earlier. All the 2D dif f raction patterns y ou created with fit2d should show up. If you select one of the datasets and click on view, y ou should be able to plot it. You can zoom in, and do many other things. Play around and explore! If the data does not show, try to set the instruments paramaters (see below). Maud will not plot the data if the data in the ESG f ile is inpatible with the instrument. Setting up instruments parameters Maud instrument window In this same dataset window, select the general tab, edit the dif f raction instrument, and y ou39。 ll end up with the Instrument Window. For radial dif f raction experiments, select  Intensity Calibration: none cal, no option  Angular Calibration: Flat Image Transmission, options: entre the correct Detector Distance, in millimeters  Geometry: Image 2D, options: select Monochromator  Measurement: 2 theta, no option  Source: Synchrotron, option: entre the correct Wavelength in angtroms  Detector: Scintillation, no option. There are many other options f or the Angular Calibration (tilt, beam center...), they will be ref ined later on. New 01/20/2020! Also, in the Aberations tab, make sure that the assymetry coefficients are set to 0. In general sy nchrotron data should not use those parameters. Restriction of the data interval In this same dataset window, in the general tab, y ou hav e the option to restrict the 2 theta interv al to work on. Enter the minimum and maximum v alues of 2 theta y ou want to work with, and press Apply Now. The 2 theta interv al has to be selected in a way that y ou hav e relev ant data f or all orientations. You should also inspect ALL patterns f or orientations and make sure that nothing is wrong (large spot, weak intensity because of a beam stop...). If any thing is wrong, simply remov e the spectra f or this orientation (hit Remove). I y ou hav e an interv al ov er which the data should be ignored, y ou can set it up in the Excluded Region tab. Click Add Term and enter the 2 theta range y ou want to exclude. Phases Phase def inition in Maud In the main Maud window, on the right side, select the Phases tab. It should be empty. You can create a new one (box icon, right next to the ey e) or load a sample f rom the database (f ollowing icon). Things are much easier if y our material is in the database:  click on the icon  select the f ile in the Maud directory  if y ou39。 re lucky, your phase is in the list... If y our material is not in the database, y ou39。 ll hav e to create a new phase:  click on the icon: it39。 ll add a phase called phase_x in the phase list  select the phase_x and click on the eye icon (edit): y ou39。 ll end up with the phase window,  in the General and Structure tab, enter the inf ormation on y our material. Save the file At this point y ou are done with the initial setup. You should sav e ev ery thing bef ore starting to y our ref inement:  in the File menu, select the option Save As  choose a f ile name with the .par extension. First Step： Manual Adjustment Incident intensity and first background parameter At this point, a few parameters can be adjusted by hand: incident beam intensity and background... Maud with a calculated spectrum Manual adjustment of parameter First, you should calculate a spectrum: in the main Maud window, click the the Calculator icon, and the Maud window should look like this:  in black: the calculate pattern,  in blue: the experimental data, both for the first azimuth. Unless you39。 re really lucky, it39。 s probably very far off... Now, Maud has a very good function that allows you to manually adjust paramaters and see the effects immediately:  in the main window, select the Dataset panel, and edit your dataset (click on the eye icon)  in the dataset window, select the Datafiles panel, and select on of the spectra,  click on View,  in the View window, select the Tools menu and Change Parameter option, and you should end up with something like the screen shot that allows you to manually adjust parameters. In the panel, adjust both  Intensity (scale factor)  Background Polynomial Coef 0 of the Dataset in order to get something reasonable. You will notice that your peaks do not exactly match the experimental data in terms of  peak positions,  peak profiles,  ratios of intensities,  high order background parameters... We will now adjust all of this with a real refinement... Maud plot window after a first manual refinement Global Refinement Rietveld Refinement Refinement of parameters with Maud In the main Maud window, the parameters to refine are located in the main window, below the plots. You can force the refineme nt of a parameter by clicking on Fixed, it should bring up a menu to set it to Refined... Incident intensity, detector distance, and main backgrounds Forcing Maud to refine intensities As a first step, we will refine:  the incident intensity  the sample to detector distance  the main background paramaters, under dataFileSet_x, background polynomial coeff 0, background polynomial coeff 1 and background polynomial coeff 2. Once you have made those parameters as Refinable, hit the hammer icon (on top of the window), and yo u39。 ll see the refinement results. Once the refinement is finished, in the bottom panel, you can see the new value of the parameters, and an error. If this erro r is equal to 1, there was an error: Maud is not able to refine this parameter. You can plot the result in many way:  by going back into the dataset, selecting a datafile, and hitting View.  in the main。