CMA Analytical Workshop Day 1 24th April 2012 XRD/ XRF

CMA Analytical Workshop Day 1 

24th April 2012 

XRD/ XRF 

Robbie Goodhue 

CMA Analytical Workshop: XRF & XRD 

Robbie Goodhue, Department of Geology

Discovery of x-rays 

8 th November 1895 Wilhelm Röntgen 



Discovery of x-ray diffraction 

X-ray beam 

Copper sulphate 

Photographic paper 

Max von Laue 



Determining crystal structure using x-rays 

Lead shielding 

Slits 

Crystal 

Ionisation 

chamber 

Rotating tables 

Braggs x-ray spectrometer (1913) 

William Lawrence Bragg 



Determining crystal structure using x-rays 

nλ = 2d Sinθ 

d 

William Henry Bragg 



Nobel Prize in Physics 

Röntgen 1901 

von Laue 1914 

Bragg & Bragg 1915 



Properties of x-rays 

1. Able to penetrate solid matter 

2. Short Wavelength 100 – 0.1 Å 

3. Able to cause fluorescence in certain chemical 

compounds 

4. Able to ionize atoms 



Philips PW1720 

‘powder XRD’ 



Diffractometer 

Soller slit 

Divergence slit 

At certain “Bragg” angles 

a diffracted beam reaches 

the detector 

Monochromator 

Shutter 

Sample 

Receiving slit 

Detector 











Peaks 

Background 



d = 1 x λ /(2Sinθ) 

26.66˚ 

λ = 1.5418Å (Cu Kα) 

d = 3.342Å 

















Help is at hand… 

The International Centre for Diffraction Data in Philadelphia holds a 

database of materials 

The ICDD 2011 Powder Diffraction File contains 715,953 unique 

material data sets 

These include organics, explosives, pigments, pharmaceuticals, 

zeolites, minerals, metals, polymers, ceramics…. 



XRD Example 1 

Investigation of defects in houses 



Irish Times, Wednesday 25 th February 2009 

In the case, Menolly was 

seeking indemnity against up to 

€60 million in damage claims 

that householders are expected 

to bring. 

Lagan’s testing has shown only 

marginal movement in the cracks, 

and this was due to changes in 

temperature. …this “blows out of 

the water” the theory… 











Proposed reaction 

FeS 2 + 2CaCO 3 + 2.5H 2 O + 3.75O 2 = FeO(OH) + 2CaSO 4 .2H 2 O + 2CO 2 

Pyrite + calcite + water + oxygen = goethite + gypsum + carbon dioxide 

EXPANSION 



Cracks propagating 

Doors jamming 

Top and bottom 

Visible bulge in 

centre of floors 

Tiles cracking 



XRD Example 2 

Polymorph detection in pharmaceutical 



Polymorphism 

‘ability of a solid material to exist in more than one form 

or crystal structure’ 

α 

β 



Quantitative polymorph determination in tablet 

Excipients 

Tablet 

API 



X-ray Diffraction (XRD) 

Rapid 

Powder sample 

40 / 60 minute scan 

~30 minute interpretation 

Cheap 

€50 per sample 

Powerful 

628,155 unique material data sets in ICDD file 



Bruker S2 Ranger 

‘ED-XRF’ 

Energy Dispersive – X-ray Fluorescence 

George Gabriel Stokes 

UV 



Generation of x-rays 

Characteristic 

radiation 

(of target) 

1.54Å 

K α 

Intensity 

Continuous 

“breaking” 

radiation 

1.39Å 

K ß 

Wavelength 



Target material - Copper 

Nucleus 

K-shell 

L-shell 

M-shell 

N-shell 




Ejected 

Electron 

Incoming photon 

K-shell 

L-shell 

M-shell 

N-shell 




1.54Å 

K α 

Kα 

Characteristic 

Radiation 

Cu K α 

Intensity 

1.39Å 

K ß 

Wavelength 

K-shell 

L-shell 

Kß 

M-shell 

N-shell 



Detection of fluorescent x-rays (Energy Dispersive XRF) 

10000 

Tube: 20 kV No filter 

Cps 

0 

30 

KeV 

0 




10000 

Tube: 

20 kV No filter 

Fe K α 

Cps 

Fe K ß 

S K α 

S K ß 

0 

30 

KeV 

6.4 

0 




10000 

Tube: 

20 kV No filter 

40 kV Al 500 µm filter 

Cps 

0 

30 

KeV 

0 



Can we obtain quantitative XRF data? 

Complexities exist: 

Matrix effects (absorption and enhancement) 

Line overlaps 

Rayleigh and Compton scatter 

Macroscopic effects 

But modern software is very advanced 



Sample preparation 

Powder and Pellet 



Sample preparation 

Fused glass disc 

Fuse sample in glass 

with lithium metaborate 

/ lithium tetraborate flux 

at 1000˚C - 1100˚C 



XRF Example 1 

Distinguishing sandstones from the Mandawa Basin 

Wellington Hudson 



The problem 

The Mandawa Basin of Southern 

Coastal Tanzania is under 

exploration for hydrocarbons and 

has several sandstone formations 

It is difficult to distinguish these 

sandstones in the field because 

they lack distinctive features 

Yet it is believed that the 

sandstones have different 

depositional histories and this 

may prove significant in terms of 

hydrocarbon exploration 



60 

0.9 

Calibration 

0.8 

Intensity (Cps) 

50 

40 

30 

20 

10 

0.7 

0.6 

0.5 

0.4 

0.3 

0.2 

0.1 

XRF Concentration (%) 

The project used XRF 

to attempt to 

discriminate the 

sandstones 

For each element, a 

calibration curve was 

established, 

using standards 

0 

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 

Concentration (%) 

Int. net 

Int. background 

Conc. XRF 

0 



K 2 0 (w t % ) 

14 

12 

10 

8 

6 

Miocene or younger 

Nangurukuru 

Kihuluhulu 

Makonde 

Nalwehe 

Mitole 

Rufiji fluvials 

Upper Kipatimu 

Lower Kipatimu 

Nondwa/Mtumbei 

Kandawale-Karoo 

XRF Results 

By plotting oxides of 

elements (K and Si) 

against each other 

discrimination of the 

Mitole Zone from the 

others is possible 

4 

2 

Mitole Zone 

Upper Kipatimu Zone 

0 

10 20 30 40 50 60 70 80 90 100 

SiO2 (wt %) 

Lower Kipatimu Zone 

Nangurukuru Zone 

Kandawale Zone 



A l 2 O 3 / C a O 

10000 

1000 

100 

10 

Miocene or younger 

Nangurukuru 

Kihuluhulu 

Makonde 

Nalwehe 

Mitole 

Rufiji fluvials 

Upper Kipatimu 

Lower Kipatimu 

Nondwa/Mtumbei 

Kandawale-Karoo 

XRF Results 

Use of other elements 

and their ratios or 

sums resolves the 

other sandstones 

1 

0 

0 1 10 100 

Fe2O3 + MgO (wt %) 

Mitole Zone 

Upper Kipatimu Zone 

Lower Kipatimu Zone 

Nangurukuru Zone 

Kandawale Zone 



XRF provides a solution 

At least five Geochemical Zones 

related to formations can be 

recognized 

With just the chemical information 

on a sample, it is now possible to 

assign it to a geological formation 

XRF offers an unbiased way of 

categorizing sandstones 



XRF Example 2 

Meteorites or Meteorwrongs? 



Hunt for the EUR500k rock 

METEORITE FIREBALL LANDS IN IRELAND 

September 4, 2003 Pat Flanagan 

IRISH treasure hunters are on the lookout for a chunk of space rock that could earn 

them up to €500,000. 

The flaming meteorite was seen hurtling through the night sky and is believed to have 

landed in north Tipperary. 

Sky-watchers gathered on the Silvermines Mountains hoping to get a good look at Mars 

were amazed when the fireball streaked above them. 

They said it was a "very bright falling star" that lit up the entire area. 

One witness added: "We saw the fireball falling at an angle almost parallel to the 

horizon. 

"First it appeared like a falling star and then it seemed to glow white ... 



“Send us 

your meteorites” 

Dr Ian Sanders 



“Finds” 

Canyon Diablo, Arizona (Iron Octahedrite Meteorite) 

Fell 20,000 – 40,000 years ago 



“Falls” 

Bovedy, Derry 

Fell (through asbestos roof of RUC Stores) 25 th April 1969 

$5490 



X-ray Fluorescence (XRF) 

Rapid qualitative assessment 

Solid / powder / liquid sample 

5 minute scan 

5 minute interpretation 

Quantitative analysis possible with calibration using suitable 

preparation and standards 

Powerful 

Most elements from Boron (Z=5) to Uranium (Z=92) 

Concentrations from ppm 



Continuous Flow 

Isotope Ratio Mass Spectrometry 

CF-IRMS 



Global abundance 

12 

6 C 

98.89% 

14 

7 N 

99.64% 

16 

8 O 

99.763% 

13 

6 C 

1.11% 

15 

7 N 

0.36% 

17 

8 O 

0.0375% 

δ (‰) = 

R sa - R std 

R std 

X 1000 

18 

8 O 

0.1995% 



Thermo Delta plus 

Flash Elemental Analyser or EA 

Gas Bench 

‘Mass spec’ 





IRMS Example 1 

Reconstructing fossil ecosystem 

Jo Hellawell 

Chris Nicholas 




Green River 

lagerstatten from 

Wyoming, USA 

Hypothesis: isotopes of nitrogen and organic carbon can be used 

to find out information about ecosystems from much further back in time, 

in order to gain some quantitative trophodynamic information about food 

webs from extinct fossil communities 



RHF2 Nearshore Quarry 



Preparation of fish 



δ 15 N vs δ 13 C 

10.0 

Average δ 15 N AIR (‰ ) 

9.0 

8.0 

7.0 

6.0 

5.0 

4.0 

3.0 

D. dentatus 

K. eocaena 

K. alta 

2.0 

-30.0 -28.0 -26.0 -24.0 -22.0 -20.0 -18.0 -16.0 

Average δ 13 C org VPDB (‰) 



IRMS Example 2 

Nutrient removal in domestic 

waste-water reed beds 

Niall O’Luanaigh 

Laurence Gill 




1.5 g of isotopically “heavy” ammonium chloride spike introduced 

15 

NH 4 -N (98% 15 N) 

Effluent collected over 64 day period, filtered and dried

CMA Analytical Workshop Day 1 24th April 2012 XRD/ XRF

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