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XRD (X-ray Diffraction) protocol: MOST

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To determine concentration using XRD:

The rule of mixtures aka Vegard's Law allows concentration of a component in a mixture to be calculated by comparing the current lattice parameter to that of each pure substance, see Wikipedia: Wikipedia:Vegard's_law

How to do XRD:

VERY FIRST THING IS TO CONTACT ED LAITILA! He is the ultimate source for XRD on campus.

Before beginning XRD

Contact the lab director/supervisor: For MTU:

  • Ed Laitila (ealaitil@mtu.edu), Office #: 628 M&M
  • XRD Lab - Room #: 629 [XRD webpage]

Ed will guide you through the XRD process & assign you a X-ray badge #. This outline here is just for review & as a procedure for what was done.

You must sign up for a time at the XRD webpage above after talking with Ed, in order to schedule your session.

How to prepare sample

XRD is generally for powder, but can be done on thin films/wet samples/etc. Consult Ed for specifics on how you should prepare your material.

1. Put on gloves

For powders:

2. Obtain alligator clip, glass, slide, spatula, and a powder sample holder (consult Ed on whether you need a special holder, ie. small amount or zero background)

3. Wash all of the above items/tools with alcohol/ethanol? in the sample prep area.

4. Clip glass slide onto powder sample holder.

5. Fill & pack w/sample powder using spatula.

6. Tap setup vertically on counter to pack and plunge spatula to free up loose areas and pack them.

7. Once the powder sample holder is packed, take off alligator clips and carefully remove slide.

8. Wipe off edges of holder w/kam wipes & alcohol?, so that the XRD does not get contaminated w/loose powder. Be careful not to ruin powder surface (You need as flat of surface as possible).

9. Now you're ready to load.


For thin films(as used in this example):

2. Obtain a small piece of clay, weight, glass slide, and specimen holder from sample prep area.

3. Clean all of the above items (except clay) with alcohol? in the prep area.

4. Make sure your sample will fit into holder. You want it to fit within the edges.

5. Ball up clay and make into a cylinder slightly higher than edges.

6. Stick clay onto sample holder.

7. Stick sample centered on top of clay.

8. Take glass slide & press it down onto the specimen to even the specimen w/holder edges. Keep glass on specimen (don't take off!)

9. Take weight while holding glass slide and put it on top of the setup.

10. Make sure specimen is larger than clay surface (no clay peeking out!)

11. Wait 5 minutes so clay doesn't shift.

12. Carefully remove weight/glass.

13. Now you're ready to load.


For others:

I've never done this, consult Ed.

Loading specimen

How to Load Your Sample
Center Sample: Pull spring-loaded platform down far enough to slide your sample in, pushing from edges, and center with center lines on the stage.  

1. Goto computer Warren.

2. Sign into the log book. Review the "How to" guide next to the log book. Make sure to record what hours the Diffractometer is at. (To find this number, look next to the red safety button)

3. If diffractometer is on. (See sheet on diffractometer for directions when it is OFF)

4.(SEE SHEET ON DIFFRACTOMETER FOR FULL DIRECTIONS) Push lever on kV knob to the left in order to turn kV knob. Turn kVs to -45.

5. (SEE SHEET ON DIFFRACTOMETER FOR FULL DIRECTIONS) Push lever on mA knob to the left in order to turn mA knob. Turn mAs to 30.

  • DO NOT EXCEED THESE SETTINGS!

6. Check slits to see if they are standard.

7. Carefully carry your prepared sample to the XRD.

8. Make sure X-rays are off.

9. Open XRD door (lift up)

11. Sample stage consists of a spring-loaded platform that holds the sample in place. Pull spring-loaded platform down far enough to slide your sample in.

12. Very carefully slide sample in and center the sample with the stage. (See pict)

13. Close the XRD door (pull down)

14. Hit the Red Safety button.

You are now ready to run the scan.

Running the XRD scan

At computer Warren (only computer associated with running scans for this diffractometer)

Open DMSNT software

  • File -> New Event List
    • Scan -> Normal
      • Browse X: Drive -> Diffraction Data -> Find your username/file or consult Ed
        • Type in name for this scan (file name)
        • Type in ID area a description of sample (specific to sample : heat treatment, composition, mech testing, etc)
    • Select Slit
      • For normal slit widths, enter as in picture.
    • Select Scan
      • Choose settings that will give information needed for your scan (discuss with Ed).
    • Save Event
    • Save As -> Event name too.
    • Go From Top (STARTS SCAN)
      • Do you want to initialize hardware? -> Yes
        • Confirm goniometer position (discuss with Ed)
          • Select Real-Time Display in Scan Status Window to watch progress.

Analysis after Scan is done

Depending on what your goal is, this can be done different ways. Consult Ed about specifics to analysing your scan.

This consists of :

Locating peaks and specifying them in the program (or having the program find them for you)

Curve fitting

Comparing them to literature data for known components in your sample or searching to find ones that fit your peaks.

Etc... then using this data to achieve your goal.