outline 1) micro-xrf 2) confocal m-xrf in the laboratory 3) ge … · 2018-08-06 · c-m-xrf with...
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Micro-XRF, Confocal M-XRF and GE-XRS
for Trace Analysis
Osaka City University: Kouichi Tsuji
1) Micro-XRF
2) Confocal M-XRF in the laboratory
3) GE-XRS including GE-EPMA
DXC2018 Workshop: Trace Analysis, K. Tsuji1
Outline
Point analysis Line analysis
1) Micro-XRF analysis
Elemental mapping
2
X-ray tubeDetector
Ar
Micro x-ray beam is created by
using polycapillary focusing
optic.
X-ray fluorescence emitted in
the path of micro x-ray beam is
detected.
DXC2018 Workshop: Trace Analysis, K. Tsuji
Amplifier
SDD
ADC
MCA
Motor driversSample Stage
(x, y, z)
Micro-XRF Setup
3DXC2018 Workshop: Trace Analysis, K. Tsuji
Motor controller
X-ray tube
Polycap.
Focal point
Point X-ray source
Polycapillary optics
(monolithic type)
Full lens; Point to point Half, semi lens; Point to parallel
N. Gao, K. Janssens,
Chap.3.3,“Polycapillary X-ray Optics”
In the book,” X-Ray Spectrometry”,
Eds. K. Tsuji, J. Injuk, R. Van Grieken,
Wiley, 2004.
It is important to use a fine focused
x-ray tube.
4
θ
X-ray total reflection
in capillary
DXC2018 Workshop: Trace Analysis, K. Tsuji
Polycapillary X-ray lens (XOS)
Polycapillary full lens - Focal spot size: ≤10 mm, [email protected]
Input focal distance : 30.0 mm
Output focal distance : 2.5 mm
Optic enclosure length: 99.5 mm
5
Polycapillary half lens- Focal spot size: ≤10 mm, at 17.4 keV
Input focal distance : 3.0 mm
Optic enclosure length: 36 mm
DXC2018 Workshop: Trace Analysis, K. Tsuji
X-Y-Z stage
SDD
X-ray tube
Sample: Au wire
Polycapillary X-ray lens
Polycapillary X-ray lens (XOS)
24 m
m83.5
mm
2.4
mm
0 20 40 60 80 100
0
50
100
150
200
250
300
350
XR
F Inte
nsity /
cps
Scanned distance / mm
FWHM
9.64 mm
0 200 400 600 800 1000 1200 1400 16000
20
40
60
80
100
120
Distance from the focal point of PCXL / mm
Focal spot siz
e o
f A
u L
a/ m
m = tan-1 (a / b) :
84 mrad
DXC2018 Workshop: Trace Analysis, K. Tsuji
Laboratory-made micro-XRF setup
Divergence
of the beam
Ca
400 mm
1300
cps
0
cps
P
400 mm
15
cps
0
cps
Sr
400 mm
12
cps
0
cps
Scanned distance / mm
XR
F Inte
nsity o
f S
r Ka
/ cp
s
Center of the otolith
Time spent in the sea
(about 6 months)
Time spent in the river
0
10
20
30
40
50
0 500 1000 1500 2000
DXC2018 Workshop: Trace Analysis, K. Tsuji
Micro-XRF analysis of otolith of Ayu-fish
Ayu is migratory fish
between river and sea.
Trace elements that Ayu
took accumulate at
otolith day by day like
tree ring.
(a few mm per day)
Since Sr is rich in the
sea, Sr distribution gives
us the period the Ayu
spent in the sea.
2) Confocal M-XRF
8DXC2018 Workshop: Trace Analysis, K. Tsuji
2-1) LLD of C-M-XRF in vacuum
9DXC2018 Workshop: Trace Analysis, K. Tsuji
X-ray transmission in air, He, and vacuum
10
Calculated X-ray transmission in 3 cm
in air, He-gas, and vacuum conditions
DXC2018 Workshop: Trace Analysis, K. Tsuji
Soft x-rays
Confocal M-XRF in He gas
11
Experimental setup of confocal micro-XRF instrument
with plastic bag including He gas
DXC2018 Workshop: Trace Analysis, K. Tsuji
12
XRF peaks of Al Ka (1.49 keV), and Ti Ka (4.51 keV)
Confocal-M-XRF spectra in air and He gas
Al plateTi plate
DXC2018 Workshop: Trace Analysis, K. Tsuji
Vacuum Chamber
Detector
X-ray tube
CCD
C-M-XRF with vacuum chamber at OCU
13
A vacuum confocal
XRF was developed
at OCU with helpful
suggestion from ATI
TU-WIEN
DXC2018 Workshop: Trace Analysis, K. Tsuji
14
Baseplate
Sample stage
Stage
Polycapillary
X-ray optics
Detector snout
Vacuum chamber
Door
Stage
T. Nakazawa and K. Tsuji, Development of a high resolution confocal micro-XRF
instrument equipped with a vacuum chamber, X-Ray Spectrom., 42 (2013) 374-379.
C-M-XRF with vacuum chamber at OCU
The sample is placed
horizontally.
Side view
DXC2018 Workshop: Trace Analysis, K. Tsuji
Confocal micro-XRF spectra in air and in vacuum
1
10
100
1000
10000
100000
0 2 4 6 8 10 12 14
XR
F In
ten
sity
/ 1
00
0 s
ec
Energy / keV
air
vacuum
NIST SRM 621
Na
Al
Si
S Fe
K
As
Ca
Ca
Ba, Ti
Rh
15
Si
(Mo target)
(Rh target)
In air
In vac.
16DXC2018 Workshop: Trace Analysis, K. Tsuji
LLDs of
confocal setups
for SRM621
(glass standards)
in air and in
vacuum
Element In air [ppm]
In vaccum[ppm]
Na - 5504
Al - 80
Si 17842 46
S 254 46
K 91 36
Ca 47 28
Fe 7 19
W : concentration (%)t : measuring time (s)INet : net intensity(cps)IBG : background intensity (cps)
QXAS, developed by The IAEA
Seibersdorf Laboratories, was
used for analysis.
Shaping time: 3 ms (SRM621),
17
Confocal micro-XRF analysis in air and in vacuum
DXC2018 Workshop: Trace Analysis, K. Tsuji
2-2) LLD by M-XRF and
Confocal M-XRF
18DXC2018 Workshop: Trace Analysis, K. Tsuji
19
Micro-XRF setup Confocal micro-XRF setup
Without the collecting x-ray lens
Comparison of two setups
⚫ X-ray tube (Rh target): 50 kV, 0.60 mA (30 W, max. 50 W)
⚫ SDD: Vortex (SII Nano Technology): 50 mm2, 128eV @ MnKa
⚫ Polycapillary optics (XOS, spot size: about 10 mm)
DXC2018 Workshop: Trace Analysis, K. Tsuji
XRF Spectra of SRM621 by m-XRF and Confocal-XRF
To evaluate the sensitivity and lower limits of detection (LLDs) of the
spectrometers a NIST SRM 621 (Soda-Lime Container Glass) was measured
in vacuum.
1
10
100
1000
10000
100000
0 5 10 15 20
Inte
nsi
ty /
10
00
se
c
Energy / keV
micro-XRF confocal-XRF
Na
Al
Si
S
Rh
-L
RhRh
, co
mp
.
K
Ca
Ca
BaBa
Cr
Fe
Fe As
SrZr
Cr
◆ Difference of analyzing volumes in
two setups,
◆ Low transmission efficiency of
polycapillary lens, especially in high
energy region
20
21
Transmission efficiency of polycapillary optics
N. Gao, K. Janssens,
Chap.3.3,“Polycapillary X-ray Optics”
In the book,” X-Ray Spectrometry”,
Eds. K. Tsuji, J. Injuk, R. Van Grieken,
Wiley, 2004.
DXC2018 Workshop: Trace Analysis, K. Tsuji
Elementmicro-XRF LLD [ppm]
Confocal micro-XRF LLD
[ppm]
Na 6990 5504
Al 159 80
Si 98 46
S 53 46
K 45 36
Ca 30 28
Fe 4 19
As 13 -
Zr 24 -
Ba 74 68
Large analyzing
volume
Small limited
Analyzing volume
22
LLDs evaluated by the same instrument
2-3) Application of
Confocal M-XRF
23DXC2018 Workshop: Trace Analysis, K. Tsuji
Analytical modes by Confocal M-XRF
Depth selective
elemental mappingCross sectional,
Depth elemental imaging
24DXC2018 Workshop: Trace Analysis, K. Tsuji
Depth 0 mm 50 mm 100 mm 150 mm 200 mm 250 mm
Ca
K
Cl
S
Zn
500 mm
Ca
K
Cl
S
Zn
Ca
K
Cl
S
Zn
Ca
K
Cl
S
Zn
Ca
K
Cl
S
Zn
Ca
K
Cl
S
Zn
DXC2018 Workshop: Trace Analysis, K. Tsuji
X-ray elemental mapping of sardine fry
Zn
500 mm
Cl
500 mm
Ca
K S
500 mm500 mm
500 mm 500 mm
1.0
0
Rela
tive in
ten
sit
y / a
.u.
1.0
0
Rela
tive in
ten
sit
y / a
.u.
1.0
0
Rela
tive
in
ten
sit
y /
a.u
.1.0
0
Rela
tive
in
ten
sit
y /
a.u
.1.0
0
Rela
tive
in
ten
sit
y /
a.u
.
DXC2018 Workshop: Trace Analysis, K. Tsuji
3D-XRF imaging of sardine fry
Analytical modes by Confocal M-XRF
27
Liquid
Solid
Depth selective
elemental mappingCross sectional,
Depth elemental imaging
27
SampleX-ray tube
SDD
Confocal Micro-XRF setup and sample
Mo target, 50 kV, 0.6 mA
X-ray tube
MCBM 50-0.6 B (rtw, Germany)
Sens. area: 50 mm2 <130 eV at Mn Ka
Polycapillary X-ray lens (XOS) :10 mm
Vortex EX-60 (Hitachi high-tech science co.)
SDD and lens
Spatial resolution: 14.5 mm@Au Lα
Steel sheet with plating Zn layer
Thickness
C Si P
Mn Fe
Al Fe Zn
P Mn Ni Zn
Al Si Ti SnCoating layer
Chem. conversion
Plating Zn layer
Steel sheet
15 mm
2 ~ 3 mm
10 mm
Element
Scratch
X-ray
tube
(Mo)
SDD
X-Y-Z stage
Sample
3.5% NaCl
solution
450 mmKapton
Sample cell and experimental procedure
Teflon (PTFE) case
29
CupCap
Polycapillaries
Steel sheet was placed in the sample
cell.
NaCl solution (3.5 mass%) was filled
in the sample cell.
DXC2018 Workshop: Trace Analysis, K. Tsuji
30
X-ray tube
Kapton film
Standard solutions
Surface of
solution/
ppm
500 mm
depth from
the surface/
ppm
Cr 14 31
Mn 11 19
Fe 11 21
SDDLinear calibration curves were
obtained for standard solutions.
Limit of Detection of metals in solution by Confocal-M-XRF
LOD depended on the depth
for evaluation. 0 20 40 60 80 100
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
Inte
nsi
ty /
cps
Concentartion / ppm
Cr
25, 50, 75, and100 ppm Cr in HNO3
DXC2018 Workshop: Trace Analysis, K. Tsuji
Scanned distance / mm
Fe
Ti
Zn
Mn
NaCl solution
Steel sheet
0
200
400
600
0
200
400
600
0
200
400
600
0
200
400
600Sca
nn
ed
dis
tan
ce
in
de
pth
/ m
mElemental maps in 0-24 hours (after one day)
24 hours / image
Start
End
Analyzed area: 1680 mm x 600 mm
Step size : 15 mm x 10 mm
Scratch
Zn
Mn
Fe
Ti
0
200
400
600
0
200
400
600
0
200
400
600
0
200
400
600
Elemental maps in 120-144 hours (after 6 days)
Blister-type corrosion
was observed
Scanned distance / mm
Scan
ned
dis
tan
ce
in
dep
th / m
m
Fe and Zn were dissolved and enriched inside the blister.
Zn
Mn
Fe
Ti
0
100
200
300
400
500
0
100
200
300
400
500
0
100
200
300
400
500
0
100
200
300
400
500
Elemental maps in 240-288 hours (after 11-12 days)
Scanned distance / mm
Sca
nn
ed
dis
tan
ce
in
de
pth
/ m
m
Zn, Fe and Mn under the blister were diffused in the
solution, and enriched near the Kapton film.
Corrosion process was successfully visualized.
Advantages of C-M-XRF
⚫ A trace analysis of 3D localized region is possible inside of the sample.
⚫ Elemental mapping for solid and liquid samples is possible.
DXC2018 Workshop: Trace Analysis, K. Tsuji
3) Grazing Exit XRS
35DXC2018 Workshop: Trace Analysis, K. Tsuji
We can apply micro beam of x-rays,
electrons and charged particles in
GE-XRS.
The surface of the sample
should be entirely flat.
X-Ray Spectrometry:
Recent Technological
Advances. Edited by K.
Tsuji, J. Injuk and R.
Van Grieken, 2004
John Wiley & Sons, Ltd
Refraction of X-Rays
GE-XRS is useful for surface sensitive x-ray analysis.
In side the sample
DXC2018 Workshop: Trace Analysis, K. Tsuji
M. Claes, K. Van Dyck, H. Deelstra, R. Van Grieken,
Spectrochim. Acta B, 54 (1999) 1517.
LLD for Si in organic
materials was reported
in ppb level.
P.K. de Bokx, H.P.
Urbach,
Rev. Sci. Instrum.,
66 (1995) 15.
GE-XRF
WDS
Good Combination of
GE-XRF with WDS
XRF intensity under total reflection of x-rays
)/2exp()/2exp()( ppj
r
pjppj
t
pjpj zNiEzNiEzE +−=
Electric filed intensity at depth-z in layer-j
Multi-layer model for calculation
視射角p
層jにおける屈折角pjN
glancing angle
reflection angle in
the layer j
K. Tsuji, K. Hirokawa, J. Appl. Phys., 75 (1994) 7189.
"'
0
"2
'
0
2
)2/()()/(
)2/()()/(
pjpjpjpj
pjpejjApj
pjpjpejjApj
iffff
frAN
ffrAN
++=
=
+=
pjpjpj in −−=1
pjpjppj
jppjpjpj
jppjjppjp
iN
NNNt
NNNNr
22
)/(2
)/()(
2
1,
1,1,
−−=
+=
+−=
+
++
XRF intensity under grazing exit condition
Multi-layer model for calculation
K. Tsuji, K. Hirokawa, J. Appl. Phys., 75 (1994) 7189.
We can calculate XRF
intensity under GE
condition in the similar
way as TXRF by
considering reciprocity
theorem.
The reciprocity theorem in optics is described as “a point
source at P0 will produce at P the same effect as that of a
point source of equal intensity placed at P will produce at P0”.
PP0
dzzNiE
zNiE
zNiE
zNiEI
ffj
r
fj
ffj
t
fj
ppj
r
pj
d
ppj
t
pjfj
j
2
0
)/2exp(
)/2exp(
)/2exp(
)/2exp(
+
−
+
− Glancing
incidence
process
Grazing exit
process
◆ GI-XRF intensity is calculated with a grazing angle of 90
◆ GE-XRF intensity is calculated with a normal incidence.
D.K.G. de Boer, Phys. Rev. B, 44 (1991) 498.
Calculation procedure is based on the theory shown in the following paper:
XRF intensity under glancing incidence and
grazing exit conditions
K. Tsuji, K. Hirokawa, J. Appl. Phys., 75 (1994) 7189.
Free software for calculation of angle-dependent XRF intensity
http://www.a-chem.eng.osaka-cu.ac.jp/tsujilab/
DXC2018 Workshop: Trace Analysis, K. Tsuji
DXC2018 Workshop: Trace Analysis, K. Tsuji
Element at top layer
Layer thickness (nm)
Substrate
Enhancement of XRF Intensity for Thin Layers under GE
K. Tsuji, H. Takenaka, P.K. de Bokx, R. Van Grieken,
Spectrochim. Acta B, 54 (1999) 1881.
Rh tube (40 kV, 70 mA), <10 Pa,
WDS (LiF200), GE-XRF (0.1 mrad step)
Ni layer : 1 nm
Carbon: 49 nm
Ni layer : 1 nm
Carbon: 50 nm
Ni layer : 1 nm
Carbon: 51 nm
DXC2018 Workshop: Trace Analysis, K. Tsuji
J. Anal. At. Spectrom., 14, 1711-1713 (1999).
Experimental Setup of GE-EPMA
EPMA (JEOL: JXA 8621) Sample stage
motor
controller
EDS
sample
stepping motor
WDS
EDSWDS
Sample
Electron beam
DXC2018 Workshop: Trace Analysis, K. Tsuji
0 2 4 6 8
0
400
800
1200
出射角: ~ 0°
O Ka
C Ka
Fe K
Fe Ka
Fe La
(b)
Inte
nsity (
counts
)Energy (keV)
0 2 4 6 8
0
2000
4000
6000
8000
出射角: 45°
O Ka
C KaAu Ma
Fe Ka
Si Ka(a)
Inte
nsity (
co
unts
)
Energy (keV)
Exit angle : 45 Exit angle : ~0
X-Ray Spectra in GE-EPMA (EDS)
Fe2O3 ( 1 mm)
Au
Si
(1 mm in diameter)
DXC2018 Workshop: Trace Analysis, K. Tsuji
A single particle
analysis is possible.
GE-EPMA of inclusion in Stainless steel
Inclusion
Inclusions (about 0.2mm ) Extracted inclusions on carbon film
Inclusion
49
a b
Tohru Awane, et al.,
“Grazing Exit Electron Probe Microanalysis of Submicrometer
Inclusions in Metallic Materials”,
Analytical Chemistry, Vol.75, pp.3831-3836, 2003.
DXC2018 Workshop: Trace Analysis, K. Tsuji
e-
30°
Steel
30°
0.4°
30°
GE-EPMA of a
single inclusion
Exit angle: 30°
Exit angle: 30°
Energy (eV)
50
Carbon
Information
Inclusion + steel
Steel
Single inclusion
Extracted inclusion
A single inclusion analysis by GE-EPMA
Quantitative GE-EPMA of inclusion on the steel
Conventional EPMA of
extracted inclusion
GE-EPMA
51
Quantification was
possible
without influence of steel.
No- sample preparation.
DXC2018 Workshop: Trace Analysis, K. Tsuji
Calculation of Electron-Induced X-ray
Intensities at Grazing Exit Angles
Calculation of GE-EPMA Intensities
K. Tsuji, K. Tetsuoka, F. Delalieux, S. Sato,
e-Journal of. Surface and Nanotechnology
1, 111-115 (2003).
Monte Carlo simulation for Si
wafer by CASINO program.
Depth distribution of Si Kα
X-rays. (e-: 20 keV, 100,000)
To improve spatial resolution
in EPMA analysis・・・・
K. Tsuji, K. Tetsuoka, F. Delalieux, S. Sato,
e-Journal of Surface and Nanotechnology
1, 111-115 (2003).
Volume of x-ray production
was evaluated by Monte
Carlo simulation (Casino
program).
DXC2018 Workshop: Trace Analysis, K. Tsuji
GE-EPMA of Ni Films on Si wafer
e-J. Surf. Sci. Nanotech. Vol. 1 (2003) 111-115
Calculation of Electron-Induced X-ray Intensities under
Grazing Exit Conditions
Kouichi Tsuji, Kouhei Tetsuoka, Filip Delalieux, Shigeo Sato
DXC2018 Workshop: Trace Analysis, K. Tsuji
Advantages of GE-XRS
⚫ Micro beam such as x-ray micro beam, electron beam and charged particle beam can be applied for surface trace analysis of localized region.
⚫ A single particle analysis is possible by GE-EPMA.
DXC2018 Workshop: Trace Analysis, K. Tsuji
Summary
• Confocal micro-XRF in vacuum is useful for improving DLs at localized small region.
• C-M-XRF was applied for monitoring of corrosion process of steel sheet in NaCl solution.
• Grazing Exit XRS is useful for surface sensitive x-ray trace analysis. Micro beams such as x-rays, electrons and charged particles can be applied for primary beam. In this case, localized surface analysis was possible.
56DXC2018 Workshop: Trace Analysis, K. Tsuji