More information on Olympus XRF and XRD solutions: http://bit.ly/1pZ3zBo In this presentation learn how our TERRA and BTX II sample cells are used along with their analytical benefits. Our X-ray Fluorescence (XRF) and X-ray Diffraction (XRD) Analyzers provide qualitative and quantitative material characterization for detection, identification, analysis, quality control, process control, regulatory compliance, and screening, for metals and alloys, mining and geology, scrap and recycling, environmental and consumer safety, education and research, and general manufacturing. To request more information or for a quote, contact us: http://bit.ly/1wh9SWM Sign up for our newsletter: http://bit.ly/1j5FOTy

1. Choosing the Right
XRD Sample Cell

2. TERRA and BTX II sample cells
have 3 size options for the spacer
Sample cell holder
Front window
Back window
Spacer
Spacer options:
•175 µm (standard)
•100 µm
•75 µm
Spacer
WindowWindow
Side View
X-ray Path

3. X-ray interaction with a sample
Diffraction: X-rays hit the sample and are bent at an
angle related to their energy and the size of the
crystal structure.
Fluorescence: X-rays strike an atom, knocks out an
inner electron. When the outer electron falls down to
replace the removed electron, it lowers in energy.
Energy difference is given off as an X-ray which the
detector measures.
Absorption: X-rays are absorbed by the sample and
do not get through the detector.
Incident X-ray
Incident X-ray
Crystal sample
Crystal sample
Incident X-ray
Crystal sample
Based on the sample chemistry the X-rays can interact in
different ways – Diffraction, Fluorescence or Absorption

4. Increasing peak-to-noise ratio
The goal is to limit fluorescence and absorption
effects to produce high peak-to-noise ratio for a
more identifiable diffraction pattern
• The spacer determines the thickness of the sample which can
influence how x-rays interact with the sample
• A smaller spacer size reduces the amount of sample under the X-
ray beam which reduces the diffracted intensity.
• If the sample is subject to secondary fluorescence or absorption,
this will also reduce the amount of that effect. It is a compromise of
the diffracted intensity and fluorescence or absorption effects to
optimize peak-to-noise ratio.
• Many samples are not subject to strong secondary fluorescence or
absorption and 175 um spacer is optimum.

5. Using sample density as a
guideline for spacer choice
Changing spacer size will require an adjustment to the
particle size of your sample for proper convection. A rough
guideline for the spacer and sieve size based on sample
density is:
* Mix the sample with ~50% glass to reduce the effective density
SAMPLE DENSITY SPACER SIZE SEIVE SIZE
3 g/cm3
175 µm 150 µm
5 g/cm3
100 µm 75 µm
8 g/cm3
75 µm 50 µm
10 g/cm3
* 75 µm 50 µm

6. Increasing signal with spacer choice
Overlay of 175 um (blue) and 75 um (red) patterns.
Note the higher intensities for the thinner spacer.
Zoom of overlay of 175 um (blue) and 75 um (red) patterns.
Note the higher intensities for the thinner spacer.
Using a thinner
spacer allows more
X-rays to make it
through the sample to
the detector which
increases signal.
In this example lead
ore was originally
tested using a 175µm
spacer. High Pb-
containing samples
will strongly absorb
X-rays generated by
a Cu or Co source.
Switching to a 75µm
spacer increased the
counts by 40%.

7. Choosing the right spacer
• Olympus applications support can assist
in choosing the right spacer and tuning the
calibration for the specific spacer to get
the best results for your application.
• X-ray tube choice can also influence peak-
to-noise ratio so this should be considered
when purchasing an instrument.

8. Contact Olympus Applications Support
ani.applications_support@olympus-ossa.com
BTX-II
Benchtop XRD
TERRA
Portable XRD

9. For more information visit our website:
www.olympus-ims.com
Thank you!

10. For more information visit our website:
www.olympus-ims.com
Thank you!