Add XRD Measurements

This guide explains how to add X-ray Diffraction (XRD) structural characterization data to your combinatorial library in NOMAD Oasis.

Overview

XRD provides structural information including crystal phases, lattice parameters, and orientations. This guide covers:

• Creating an XRD measurement entry
• Uploading multiple data files
• Reviewing auto-generated diffraction plots
• Managing measurement points

Prerequisites

Before starting, you need:

• Completed sputtering upload with combinatorial libraries
• XRD data files - Individual files for each measured point
• Knowledge of which quarter you measured (BL, BR, FL, FR)

File Format

XRD files are typically .xy, .xrdml, .raw, or similar formats containing 2θ angle vs. intensity data.

Step 1: Prepare Your XRD Files

Organize your XRD data files. They should look like:

Measurement Strategy

• Full quarter mapping: Upload all points from one quarter
• Selected points: Upload specific interesting positions only
• Individual points: Upload single positions for quick checks

Quarters uploaded individually are recommended for organization.

Step 2: Navigate to Your Upload

1. Go to the sputtering upload where your combinatorial libraries were created

2. Click on the upload to open it

Step 3: Create XRD Measurement Entry

3.1 Start Schema Creation

Click "Create from schema" in your upload.

3.2 Name and Select Schema

Follow the naming convention:

username_####_Material_Quarter_XRD

Examples:

• amazingresearcher_0042_CuZn_BL_XRD (back left quarter)
• username_0123_BaZr_FR_XRD (front right quarter)

Select the schema:

• Choose "XRD Measurement" from the Built-in schemas dropdown

Click "Create".

Step 4: Upload XRD Data Files

4.1 Locate the File Upload Field

Scroll down to find the "Data files" field in the XRD measurement entry.

4.2 Upload Multiple Files

1. Select all your XRD data files for this quarter:
2. Use Ctrl+Click (Windows/Linux) or Cmd+Click (Mac) to select multiple files

3. Or drag and drop all files at once

4. Upload to the "Data files" field

1. IMPORTANT: Click "Save" immediately after upload completes

Must Save!

Always click "Save" after uploading files. Unsaved uploads will be lost.

Processing

NOMAD processes each XRD file to extract:

• 2θ angle ranges
• Intensity patterns
• Measurement positions on the sample
• Peak positions and intensities

Step 5: Review Results

5.1 Navigate to Results Subsection

Scroll down to the "Results" subsection and expand it.

5.2 Examine Auto-Generated Plots

NOMAD automatically generates visualizations showing:

• Individual diffraction patterns for each point
• Overlay plots comparing multiple positions
• 2θ vs. intensity for all measurements

All measurement points are displayed in the graphs, allowing you to:

• Compare phases across composition space
• Identify structural transitions
• Locate amorphous vs. crystalline regions

5.3 Optional: Remove Invalid Points

If you measured incorrect positions (bare substrate, wrong sample, etc.):

1. Locate the data point in the list

2. Click the trash can icon next to the invalid point

3. Click "Save" after deletion

When to delete points

Unlike EDX where substrate hits are common, XRD measurements are typically more controlled. You'll rarely need to delete points unless you explicitly measured the wrong location.

Step 6: Repeat for Additional Quarters

If you measured multiple quarters, repeat this process for each:

1. Create a new XRD Measurement entry with the appropriate quarter identifier:
2. username_####_Material_BR_XRD
3. username_####_Material_BL_XRD
4. username_####_Material_FL_XRD

5. username_####_Material_FR_XRD

6. Upload the corresponding XRD files

7. Review results and clean data if needed

Organization Benefits

Separate entries per quarter:

• Keeps file counts manageable
• Matches physical sample division
• Enables quarter-specific analysis
• Parallels EDX organization

Verification Checklist

After uploading XRD data, verify:

• [ ] Entry named correctly with quarter identifier
• [ ] All XRD files uploaded successfully
• [ ] Results subsection shows diffraction patterns
• [ ] Data points correspond to expected positions
• [ ] Patterns show reasonable peak intensities
• [ ] Final save completed
• [ ] No obvious file upload errors

Troubleshooting

No plots appear in Results section

Problem: Results subsection is empty after upload

Solutions:

• Verify files are in supported XRD format
• Check that files aren't corrupted (open in analysis software)
• Confirm you clicked "Save" after upload
• Refresh the page and wait for processing to complete
• Check upload status for error messages

Some files didn't upload

Problem: Expected file count doesn't match uploaded count

Solutions:

• Check file size limits (typically <10 MB per file)
• Verify all files were selected before uploading
• Try uploading in smaller batches
• Ensure files aren't open in another program
• Check file permissions

Diffraction patterns look wrong

Problem: Plots show unexpected peak positions or intensities

Solutions:

• Verify you uploaded files from the correct measurement
• Check that files haven't been modified or corrupted
• Confirm the quarter identifier matches the actual measured quarter
• Review raw files in your XRD analysis software
• Check for correct wavelength/radiation type in metadata

Can't delete data points

Problem: Trash icon missing or not working

Solutions:

• Ensure you're in edit mode
• Check you have write permissions
• Try refreshing the page
• Verify the entry isn't published/locked

File format not recognized

Problem: Upload rejects your XRD files

Solutions:

• Check the supported file formats with your NOMAD administrator
• Export data in a different format from your XRD software
• Verify files aren't compressed (.zip, .rar, etc.)
• Ensure file extensions are correct and lowercase

Understanding XRD Data

What does XRD measure?

XRD provides:

• Crystal structure - Phase identification (cubic, tetragonal, etc.)
• Lattice parameters - Unit cell dimensions
• Crystallinity - Relative amounts of crystalline vs. amorphous material
• Preferred orientation - Texture information
• Phase purity - Presence of multiple phases

Measurement considerations:

• Penetration depth: X-rays probe full film thickness plus substrate
• Spatial resolution: Spot size typically 1-10 mm (larger than EDX)
• Substrate peaks: Silicon substrate peaks will appear in patterns
• Thin film effects: May see broad peaks or weak intensities

Data interpretation:

Use the visualizations to:

• Map phase evolution across composition gradients
• Identify composition regions with desired crystal structures
• Track structural transitions (e.g., amorphous to crystalline)
• Compare experimental patterns to reference databases

Next Steps

After adding XRD measurements:

1. Add EDX Measurements - Correlate structure with composition
2. Add Ellipsometry Measurements - Add optical properties
3. Add Other Characterization - XPS, PL, Raman
4. Jupyter Analysis - Create custom structure-property plots

Related Resources

• Upload Sputtering Data - Create parent combinatorial library
• XRD Reference - Detailed schema documentation
• Tutorial - Complete workflow example
• Characterization Techniques - Understanding XRD in context

Need Help?

If you encounter issues:

• Ask colleagues who have uploaded XRD data successfully
• Review example XRD uploads in your group
• Check the Reference Documentation
• Contact DTU Nanolab NOMAD support