1. Specimen Preparation XRD Pikes Peak 1 & 2
T. Fawcett, International Centre for Diffraction Data, Newtown Square, PA N. Bhuvanesh, Texas A&M University, College Station, TX
S. Quick, Pennsylvania State University, State College, PA
M. Rodriguez, Sandia National Laboratory, Albuquerque, NM

2. Instructors 14 Years ICDD clinic instructor
Assistant Prof. Computer Sci & Eng.
Materials Laboratory at Sandia
Specializes in in-situ diffraction, over 100 publications
Dr. Nattamai Bhuvanesh
Texas A & M University
College Station, Texas
X-ray Diffraction Laboratory, TAMU
“Principles and Applications in Powder
Diffraction”
22 Years at Dow Chemical, 10 at ICDD
Over 40 publications

3. Agenda Break at ~10:15-10:30 Introduction Tim Particle Statistics Mark
Cavity Mounts Sue
Small or thin specimens Bhuv
Our tricks All
Break at ~10:15-10:30

4. Critical References
“Preparation of Specimens for X-ray Fluorescence and X-Ray Diffraction Analysis”, Victor E. Buhrke, Ron Jenkins, Deane K. Smith (+ 30 friends), Wiley-VCH Publishers,1998
Selected Resources for X-ray Diffraction, Methods and Practices CD- ROM – “Sample Preparation Methods in X-ray Powder Diffraction” 2004
“Introduction to X-Ray Powder Diffractometry”, Ron Jenkins, Robert L. Snyder”, Wiley-Interscience Publisher, 1996
“X-Ray Diffraction Procedures for Polycrystalline and Amorphous Materials”, Harold P. Klug and L. R. Alexander, Wiley-Interscience, 1974
“X-Ray Diffraction Methods in Polymer Science”, L. R. Alexander, Wiley-Interscience, 1969 (Note: Hard to find), Kreiger Publishing, 1979

5. Specimen Preparation – Free Download, Advances in X-ray Analysis

6. Specimen Preparation Cast of thousands !
Contributions by global authors, references summarize work of many researchers
Definitions
Sample
material supplied by requestor
Specimen
portion of sample presented to instrument

7. Goal of Specimen Preparation
Prepare a specimen for the diffraction experiment which is representative of the sample to provide the information needed to answer the question posed.
Ideally, no more time and effort should be required or expended than is necessary to meet the above goal.

8. Goal of Specimen Preparation
An elaborate procedure is not necessary for phase confirmation
Know and understand the question before starting the procedure (assumes that the requestor understands what is really needed)

9. Every time you prepare a sample you change it !
Make sure the sample prep technique
is not destroying, altering or masking the original
problem (tip - analyze before and after preparation steps)
Grinding can destroy soft materials
Binders can mask or dilute phases
- Temperature and humidity can change phase chemistry
Sieving may separate phases as well as separating
particle size

10. Elements of Sample Prep
Basic statistics
Representative samples from bulk
Sampling procedures (macro)
Grinding
Absorption and microabsorption problems
Crystallinity and particle effects
Specimen configuration and equipment geometry
Depth of penetration
Surface roughness
Background, specimen holders
Crystal perfection and extinction
Concentration phases
Slurries and slurry mounts, analyzing films, flowing materials
Use of internal standards
Atmosphere sensitive or toxic materials
Special chemistries (metals, drugs, minerals, thin films, gems, explosives, polymers, nanomaterials)
Temperature and Pressure Studies

11. Container says Plaster of Paris (CaSO4). It looks
Peak Shift 0.05 degrees
Sample was
so high that
it was not in
the focusing
plane.
Container says Plaster
of Paris (CaSO4). It looks
this stuff has grabbed H2O
and CO2 from the air over time
Sample holder
Red scan – Nice data but thin preparation resulted in diffraction from aluminum substrate
Green Data – Very thin film on glass – too thin not enough intensity/particles
Black data – Thick preparation – assymmetry in the peaks but otherwise OK
Thin layer prep
CTIMP1a.raw

12. Specimen Prep – Macro to Micro
Courtesy of
PANalytical
Courtesy
FBI

13. F S

14. Macro to Micro - Mountains to molehills
Riffle Splitters
Jaw Crushers
Sample Thieves
Pulverizer
Mills (large)
Slicers & Dicers
Micro
Mortar & Pestle
Ball mill (small)
Particle Sieve
Particle size (microns)
Particle Orientation
Particle mixing

15. Resources at DXC ! Angstrom Inc. Chemplex Industries
(pulverizers, presses)
Chemplex Industries
(mills, grinding media, thin films)
Corporation Scientifique Claisse
(weighing stations)
Herzog Automation
(automated preparation systems)
Premier Lab Supply
(presses, binders)
Rocklabs Ltd
(mining and ore prep)
SPEX SamplePrep
(cryogenic mill, films)

16. What is usually going to cause you trouble?
Peak Width
Intensity - Y-Axis
Particle statistics influence intensities via orientation
Specimen displacement influences position
Both particle statistics and specimen displacement influence peak profiles
Position - X-Axis (d-spacing)