outline 1) micro-xrf 2) confocal m-xrf in the laboratory 3) ge … · 2018-08-06 · c-m-xrf with...

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


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


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


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


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


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


2-1) LLD of C-M-XRF in vacuum


X-ray transmission in air, He, and vacuum

10

Calculated X-ray transmission in 3 cm

in air, He-gas, and vacuum conditions


Soft x-rays

Confocal M-XRF in He gas

11

Experimental setup of confocal micro-XRF instrument

with plastic bag including He gas


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


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


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


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.

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


2-2) LLD by M-XRF and

Confocal M-XRF


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)


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.


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


Analytical modes by Confocal M-XRF

Depth selective

elemental mappingCross sectional,

Depth elemental imaging


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


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

.


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.


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



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


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)


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.


3) Grazing Exit XRS


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


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


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


Free software for calculation of angle-dependent XRF intensity

http://www.a-chem.eng.osaka-cu.ac.jp/tsujilab/


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


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


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)


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.


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.


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).


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


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.


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.


outline 1) micro-xrf 2) confocal m-xrf in the laboratory 3) ge … · 2018-08-06 · c-m-xrf with...

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