Introduction

This guide is an introduction to the HighScore Plus software used to solve crystalline phase identification.

HighScore for scientists is available on a virtual computer onboard.

To access the Remote desktop click on the windows tab and type 'remote desktop', this will bring you to a window to enter an IP address. Only one person can use the remote desktop at one time. The remote desktop can be accessed from any PC onboard (windows).

Figure 1. XX

IP 165.91.150.141, username 'daq' and password 'daq'.

Getting Acquinted

To open the software double click the HighScore Plus icon on the desktop.

You can customize the main screen for your own requirements; the most common desktop used is Phase-ID and can be selected on the bottom right toolbar in the drop down menu or Select View > Desktop > Desktop Name (Figure 2).

Figure 2. XX

Main GraphicsAdditional GraphicsPatterns and List Window.

Figure 3. Basic Layout of the "Phase-ID" Display.

For the Phase-ID Desktop display, you have three main windows (Figure 3).
The Main Graphics window shows the scan and/or scans in the Analyze View.
The Additional graphics window displays the zoom overview.
The Pattern List is the third panel on the right of the screen can be used to examine the Peak List, Scan List, Quantification Graphs, and the Anchor Scan Data.

Opening a Diffractogram in HighScore Plus

To open a diffractogram for evaluation, click File>Open (Figure 4).

Figure 4. Open Scan

Select the file you want to open. HighScore software can import files produced by Bruker D4 XRD or Panalytical AERIS XRD the file formats include .raw, .uxd, and .xrdml files.

• If you do not see the file you are looking for in the field Files type, select All files (.). This will bring up XRD files produced by the Bruker D4 or Panalytical AERIS.
• You can select multiple files; each one will open in its own window.

Click Open. The Scan is now open and ready for evaluation.

HighScore: Phase Identification

Diffraction pattern treatment is used for phase and crystallographic analyses. The two most important treatments are background determination and peak search. A proper background determination is very important for phase analysis.

There are several steps used when you want to determine the identity of the unknown phases in the diffraction pattern.

1. Background determination
2. Peak search
3. OPTIONAL – Strip K-alpha2 Signal
4. Peak Search and Match

Removing the Background

Background fitting is often easier if the y-axis is set to 'Square Root Y-axis' (Figure XX). To subtract the background, select Treatment > Determine Background (Figure 5). The background is automatically determined (fluo green line on the diffractogram in Figure 5).
The Determine Background window will show on the screen (Figure 3).

Figure 3. Determine Background Window.

 
Automatic background fitting is most often used. Adjust parameters until the green background line is a good fit to the data, without overfitting or underfitting the data. You will want to choose your bending factor and a granularity.

You can change the Bending factor by moving the slider on the Determine Background window. This field adjusts the nonlinearity and curvature of the background. Typical values are between 0 and 4 (normally a small number 1-2 fits well).
You can change the Granularity by moving the slider. This field changes the number of intervals used for background determination. Typical values range between 10 and 30. The default value of '20' fits most ordinary scans.

Tick the box 'Use smoothed input data' to avoid oversampling.

When the background is fit, click Accept to accept the background (Figure XX). The Determine Background window is closed and the accepted background is displayed as a dark green line on the Main Graphics window (Figure 4).

Once you determine the background, subtract the Background by clicking Subtract in the Determine Background window. Then click Replace. The diffractogram should be 'brought down' to base level. 

Figure 4. Main Graphics window with the background displayed as the green line.

Search Peaks

Select Treatment > Search Peaks. The Search Peaks window opens (Figure XX). Adjust the peak search parameters if needed. The default settings are a good starting point.
The significance is a calculation of the probability that a possible peak is not noise-induced. A large minimum significance above 2 or more is useful for noisy data.
Normally you should not have to adjust the other values.

Figure 5. Search Peaks Window

Once you are happy with the parameters, click Search Peaks (Figure XX). Detected peaks are displayed above the Main Graphics window by orange lines (green box in Figure 6). A calculated pattern based on the peak search is shown in pink over the experimental data in red.

Click on 'icon' (Set Display of Peaks) to toggle the display of peaks.

• K-α1 peaks are indicated by solid lines
• K-α2 peaks are indicated by dotted lines
• Peaks that are not explained by a reference pattern have a little 'V' mark.

Figure 6. Main Window display selected peaks.

When you are happy with the results, click Accept button (Figure 5).

In the 'Patterns and List' window, click on Peak List tab to show the numerical details on every detected peaks (Figure XX).
In the Peak List, you can right click on a row to 'Add Peak' or 'Delete Peak' or 'Remove Selected Peak Features from Scan' (Figure XX). Peaks derived from the K-α2 wavelength are indicated by a different (gray) background color (Figure XX). Deleting certain peaks will help the software to focus on specific peaks for mineral searching. This can be helpful if you have a multiphase (multi mineral bulk sample).

Figure 7. Peak List displaying the numerical details of the detected peaks from the Peak Search

OPTIONAL – Strip K-alpha2 Signal

This step is OPTIONAL and not necessary for phase analysis or other analyses you can do in HighScore Plus. K-alpha2 radiation can be computationally stripped from the data because the relationship between K-alpha1 and K-alpha2 radiation is very well known

Primarily you remove the K-alpha peaks from the diffraction pattern to clean up the data or make it easier to evaluate good and/or poor matches.
To remove the K-alpha2 signal form your data:
Select Treatment>Strip K-Alpha2.
Click the Strip K-alpha2 button.
Click the Replace button.

Peak Search and Match

Once you have determined the background and searched for peaks the next step is to match the peaks.
Select Analysis >Search & Match > Execute Search & Match
The Search & Match window appears with a default parameters set (Figure XX). For initial searching the 'Default' parameters are fine to start with. You can adjust the parameters as necessary.

• • Data Source: Best results when you use Peak & Profile Data
    • Peak Data is the peak list produced from your peak search.
    • Profile Data is all observed intensity above the background model produced when you fit the background
  • Scoring Scheme: Set this to Multi Phase. Only use single phase if you want to force program to use a single phase to match all the observed data.
  • Auto Residue: Make sure you select this. When you accept a candidate as a good match all of the remaining candidates are rescored based on how well they fit the unmatched features.
  • Match Intensity: if this is off, the quality of the match is based only on agreement of peak positions; if this is on, the score reflects the quality of the intensity match as well.
  • Demote unmatched strong: if on, if a candidate has one strong (>50%) peak missing in the observed data then the candidate is discarded—no matter how well the rest of the peaks match.
  • Allow pattern shift: if on, each reference pattern is shifted for an optimal fit with the data. The maximum allowed pattern shift is +- 4 x FWHM.

Figure 8. Search and Match Window.

Click Search. List of the possible matches is displayed on the lower portion of the Pattern List (Figure XX). Click OK to accept.
The Candidates list shows entries ordered by high to low score based on how well they match the experimental data (Figure XX).

Figure 9. Candidates List ordered by strongest and weakest matches.

The next step is to manually accept candidates that have a high score and that match the peaks and features of the measurement.

For that, drag the matching candidate patterns from the Candidates list to the Accepted Ref. Patterns list in the upper half of the Pattern List tab to accept it (Figure XX). When you select matching patterns, it is highlighted in gray and lines are displayed in the Graphics window (Figure XX). Peaks will lose the "V" mark above the line. These peaks have been explained by the reference pattern. Peaks with a "V" have not been explained and/or matched (Figure XX).

There are several views in the Additional Graphics pane to support the visual comparison between reference pattern sticks and the measurement. For instance:

• Select View > Additional Graphics > Compare Mode   or
• Select View > Display Mode > Show Calculated Profile

Figure 11. Move accepted peaks from the candidate window the accepted reference pattern.

To check if the accepted patterns are indeed minerals and comply with the sample description, right-click a specific reference pattern in the Accepted Ref. Patterns list. Select Show Pattern to view the subfile information of that pattern (Figure XX).

If you wish to save the complete file (including the candidate list and the accepted reference patterns), click File > Save Document. HighScore Plus file format is .hpf.

HighScore: Rietveld Analysis: Quantitative Phase Analysis

To complete a quantitative phase analysis you will use the Rietveld refinement in HighScore Plus software.

Starting Quantitative Phase Analysis

Before completing the quantitative phase analysis, make sure you have completed all of the phase identification steps (see HighScore: Phase Identification above):

1. Determine the background
2. Search peaks
3. OPTIONAL: Strip the K-α
4. Peak Search and Match

Now you are ready to complete quantitative phase analysis using the Rietveld method. This method is a full pattern fit method. It is typically used for standardless, quantitative phase analysis.

Setting up your desktop layout

Select the desktop layout from Phase-ID to Rietveld Analysis on the Desktop toolbar (Figure 12).
View > Desktop > Desktop Name > Rietveld Analysis.
You can change the Desktop layout depending on the XRD analysis you perform in the HighScore Software.
Refinement ControlObject InspectorMain GraphicsAdditional Graphics.

Figure 12: Rietveld Analysis Desktop Layout

1. Start Analysis

Select Analysis > Fitting. Check that the option Fitting Mode is set to Automatic. Correct if necessary.
Select Analysis > Fitting > Start Fit> and then select <Phase fit> Default Rietveld to start the refinement with the default Rietveld parameters set. Wait until it is finished, this may take a few minutes (Figure XX). The peaks and the calculated profile are in the Main Graphics pane.

Figure 13: Menu guide for the phase fit default Rietveld

In the Refinement Control tab in the 'Refinement Control' window on the main display, double-click the Global Variables to open the 'Object Inspector pane' (Figure XX). Select Global Settings>Agreement Indices to view the values of the Goodness of Fit and Weighted R profile (Figure XX).

Figure XX. Refinement Control window displaying the Refinement Control, global variables. The Object Inspector can be used to look at the fit properties and agreement indices.

2. Display the Phase Amounts

The phase amounts will automatically be displayed together with the phase legend in the 'Main Graphics' pane once the Rietveld analysis is completed (Figure XXA). Alternatively, you can open the 'Quantification' tab in the 'Refinement Control' pane and view a pie chart of the quantification (Figure XXB).

Figure XX. A. Phase amounts as a percentage are displayed on the main graphics window. B. Pie chart of the phase amounts for the quantification of the phase.

3. Export and Save a File

To export a file or save the file as a working file, click File>Save As.
Save the document as a .HPF file (this is the HighScore working file format).

Archive Versions

HighScore Software QSG (Original Version 378) - 290220