ANSTO Accelerator Capabilities for Materials Characterisation

Mihail Ionescu, Rainer Siegele, David CohenMihail.Ionescu@ansto.gov.au

IAEA Vienna15-19 Sept 2008

Outline:

• ANSTO’s Ion Beam Accelerators

• Examples from ANSTO’s research projects on the use of accelerators for characterization of materials

ANSTO’s Ion Beam Accelerators

ANTARES (Australian National Tandem for Applied Research). • Opened in September 1991.• 10 MV heavy ion machine (HVEE) with 3 ion sources and 5 high energy beamlines (2 IBA and 3 AMS).

• Can accelerate most ions in the periodic table (H- U)

STAR (Small Tandem for Applied Research). • Opened in January 2005.• 2 MV heavy ion machine (HVEE) with 3 ion sources and 3 high energy beamlines (2 IBA and 1 AMS 14C).

• Can accelerate (H, He, C)

Ion Beam Accelerators Usage

• To provide accelerator based expertise for: - internally and externally driven research with

Australian Universities, CSIRO, Local and State Governments, industry and international organisations including the International Atomic Energy Agency (IAEA)

- training for local and international researchers, workshops, fellowships etc for developing countries in our region• Main techniques include:

- Ion Beam Analysis (IBA): PIXE, PIGE, RBS, ERDA, RToF, NRA and Heavy ion µ-probe (X-ray mapping; lithography; IBIC)

- Accelerator Mass Spectrometry (AMS) – 14C, 10Be, 26Al, 129I, Actinides

ANTARES

ANTARES10 MV Tandem

HVEE 846multi sample

860single

NECalphatross

Microprobe

IBA-ToF

AMS: C, Be, Al

AMS:Actinides

10m• Microprobe: µ-PIXE; µ-RBS• ToF: Heavy ion ERDA; RBS; ion implantation• AMS: 14C, 10Be, 26Al, 129I, Actinides

5m

STAR

• SIBA1: Automated PIXE; PIGE; RBS; PESA• SIBA2: He-ERDA; Variable angle RBS; NRA• AMS (14C) dating

358Ion Source

846BIon Source

2MV HVEETandetron Accelerator

AMS 14C

IBABeam line 1

IBABeam line 2

Ionisationchamber

Recombinator

IBA Materials Projects at ANSTO• Elemental analysis (PIXE, PIGE)• Characterization of thin films near-surface layers and interfaces:

- thickness (RBS, NRA, variable angle RBS) - depth profile of elements (RBS, NRA, ERDA)- defects (variable angle RBS-channelling)- 2D mapping (µ-PIXE; µ-RBS)

• Modification of thin films, near-surface layers and interfaces:- ion implantation (conductive polymers; ZnO/STO; other)

• Device testing (IBIC, single event upset)Can do:

• Materials testing for radiation damage• Micro-machining• Ion beam induced chemical reactions

PIXE, PIGE: Aerosols in AsiaPIXE, PIGE: Aerosols in Asia

Cheju Is.

Sado Is.D

ust

S

Hong KongHanoi

Manila

• Large throughput of samples• PMF→Source identification• Events correlation (back trajectories)• Large database

Lead vs Bromine Mascot 1992-2000

0200400600800

10001200

0 100 200 300 400 500Br (ng/m3)

Pb (n

g/m3 )

Pb=(2.12±0.30)*Br +(27±29)R2=0.98

Mascot 1992-2000

01002003004005006007008009001000

D ec - 90

D ec - 91

D ec - 92

D ec - 93

D ec - 94

D ec - 95

D ec - 96

D ec - 97

D ec - 98

D ec - 99

D ec - 00

Lead

(ng/m

3 )

PIXE, PIGE: Study of Archaeological Artefacts [1]

• Non destructive• Large throughput • PMF→Source identification• Ancient trade routs identified

[1] T. Doelman, R. Torrence, V. Popov, M. Ionescu, N. Kluyev, I. Sleptsov, I. Pantyukhina, P. White and M. Clements, Geoarchaeology 23, 234, (2008)

PIXE Bremsstrahlung [1]

[1] D. D. Cohen, E. Stelcer, R. Siegele, M. Ionescu, M. Prior, NIM B 266, 1149-1153, (2008) [2] K. Murozono, K. Ishii, H. Yamazaki, S. Matsuyama, S. Iwasaki, NIM B 150, 76, (1999)

• Important for quantitative analysis• Theoretical background calculated for 3MeV protons on C[2]

Be 1843 µg/cm2

C 1767 µg/cm2

• Data corrected for self absorption; detector efficiency; γ-ray background component and normalised to unit charge

(µC), unit solid angle (Sr) and unit target thickness (µg/cm2)• Normalised yield (Yld) was fitted to a 9-th order polynomial ln(Yld)=a0+a1ln Ex+a2 (ln Ex)2+…+a9(lnEx)9

Heavy Ion MicroprobeHeavy Ion Microprobe• Spot sizes of 1-10µm• 1-10 nA target current• Focussing of ions with Me/q2 = 100 (H to U)• 2D mapping• Applications: 2D mapping (µ-PIXE, µ-RBS) Nuclear reactions Resonances Heavy Ion Elastic Recoil Detection IBIC Ion Beam Lithography

Au50 x 50 µm Cr

1-2 µm spot size at 100 pA; 3MeV H

Elemental Mapping using the Ion MicroprobeElemental Mapping using the Ion Microprobe

PIXE Spectrum of Aerosol Filter

Exposed Filter

Unexposed Filter

soil

cars

sea spray FeS ores

50µm

KCa Ni

Characterization of Characterization of MicrodosimetersMicrodosimeters by IBIC by IBIC [1][1]

Charge collection maps of 20 MeV C4+ beams onSilicon on Insulator (SOI) micro-dosimeters

K

[1] I. M. Cornelius, R. Siegele, I. Orlic, A. B. Rosenfeld, D. D. Cohen, NIM B 210, 191, (2003)

Single Ion irradiation [1]

• Damage in tracks depend on LET• Diameter of a damage track is

~10nm • Used in single ion implant and high

resolution IB lithography

Low Medium HighPMMASi

Ion E (MeV)

LET elect

(eV/nm)LET nucl (eV/nm)

H 2 15 <0.1 MARCHe 2 150 0.1 MARCC 30 44 0.3 ANSTOC 9 760 0.8 ANSTOF 8 1380 2.8 ANSTOCu 6 1460 77 ANSTO

AFM

100nm

F damagetracks

[1] A. Alves, P. Reichart, R. Siegele, P. N. Johnston, D. N. Jamieson, NIM B 249, 730, (2006)

Ni Uptake in Plants [1]

Ca

100 µm

Leaf cross-section scan : - current 0.8 nA- spot size 3 µm - count rate 2 kHz

• Study of Hybantus Floribundus- a Ni hyperaccumulator• Thin sections (~10 µm) freeze substitution• Localization of Ni in various parts of the plant

Ni

100 µm

50 µm

K[1] R. Siegele, A. G. Kachenko, N. P. Bhatia, Y. D. Wang, M. Ionescu, B. Singh, A. J. M. Baker, D. D. Cohen, X-ray Spectrometry 37, 133, (2008)

RBS: multi-layer MgB2/Mg2Si/Al2O3 [1]

50 100 150 200 250 300

0.0

5.0x103

1.0x104

1.5x104

2.0x104

75o

8x 15

nm M

g 2Si

9x 80

nm M

gB2

Yield

[cts/2µC

]

Channel No

experimental simulated B O Mg Al Si

2MeV He1+

15o

C-Al 2

O 3

• Role of Mg2Si layers in increasing the pinning• comparison with single MgB2 film• Increase in activation energy U0• Increase in anisotropy of U0

[1] Y. Zhao, M. Ionescu, P. Munroe, S. X. Dou, APL 88, 012502, (2006)

RBS: channelling in Si

200 400 600 800 1000 1200 1400

0

1000

2000

3000

4000

5000

RBS y

ield [

cts/20

0µC]

Energy [keV]

(101)

(111)

C

Surface

Surface

(101)1MeV He+

Detector

1MeV He+

Detector

(111)

• Study of Al-Ti-C MAX phase [1]• Part of C diffused in Si (001) substrate• A buried layer of C by channelling of 2MeV He+ in Si• Substrate replaced by MgO

[1] J. Rosen, P. O. A. Persson, M. Ionescu, A. Kondyurin, D. R. McKenzie, M. M. M. Bilek, APL 92, 064102, (2008)

50 100 150 200 250 300 350

0

100

200

300

400

500

600

700

C

Mg

Nd

Exp Simul C O Mg Al Ti Nd

Yield

[cts/1

.2µC

Channel No

Ti

Al

O in

MgO

HeERDA-SBD: Hydrogen in SiNx thin film [1]

recoiled (H)

)( 22 EEEE foild ∆−=dxdExEE x

x1

12cosβ−=

−=dxdExEkE x

x0

01 cosα)( 11 EEEE foild ∆−=

E0x

At depth x:2

21

221

01 )(cos4MM

MMEE+

= θ

θσ

cos4)]([

22

20

221

221

MEMMeZZ

dd +=Ω

ΩΩ

=

ddN

ctsYcmatNi

σ

αcos][]/[ 2

Ed

E2

E0E1x

M1 (He)M2 (H)

αβ

θ E1

x

scattered (He)

recoiled (He)

At the surface:

Filter

Energy Detector

N- number of ions incident on sample surfaceΩ - detector solid angleσ - scattering cross section

0 200 400 600 800 1000

0

10

20

30

40

50

60

H Yie

ld [co

unts]

Energy [keV]

Si Wafer thin SiN thick SiN

He

H

S iSiN x

:H

S urfa

ce H

• Passivating role of Hydrogen in thin SiNx films

• Depth of analysis: up to few 100nm• Depth resolution: few nm• Sensitivity: ~0.1 at%

0 200 400 600 800 100005

10152025

Depth [x1015 at/cm2]

Si

05

10152025

Hydro

gen [

x1015

H/cm

2 ]

SiN20

05

10152025

SiN70

[1] M. Ionescu, B. Richards, K. McIntosh, R. Siegele, E. Stelcer, O Hawas, D. D. Cohen, T. Chandra, Materials Science Forum Vols. 539-543, pp. 3551-3556, (2007)

ANSTO Heavy Ion ERDA-ToF [1]

T2

Secondary Electron

MCP

W electrodes C foilsRecoils

0.5m

ElectrostaticMirrors

SBD

45o

4-way slitsIon Beam

67.5o

Secondaryelectron

Anode plateEnergyTime

T1

0 25 50 75 100 125 150 175 200 225 250 275 300 325

17

18

19

20

21

22

23

24

Depth

reso

lution

[nm]

C foil thickness [µg/cm2]

82.5 MeV Iodine

• Ion beams: C; O; F; Na; Si; Cl; Ca; Ti; Co; Ni; Cu; Br; Nb; Ag, I; W; Pt; Au

• Beam shape: rectangular• Incident angle: 67.5o• Exit angle: 45o• Scattering angle: 45o• C foils: 25µg/cm2• Sample manipulation: XYZ, rotation• Sample heating up to 1,000oC• Gas ports (O, N)• Further development:

- H absorption/desorption- In-line sample preparation: ion implanter + EB evaporatorTRIG (86)

QD (821)

CH3

CH1

CH0(94)

STOP START

(T)

(93)

(E)

QD (821)

Sample

CFD

Delay

CFD

PAFPAFPA

e-e-

T2

TOF-ERDA DiagramIon Beam

Recoils T1SBD

PC

(571)AMP

(474)TFA

(463)CFD

(89)NIM-TTL(567)

TAC

(419)MCA

[1] J. W. Martin, D. D. Cohen, N. Dytlewski, D. B. Garton, H. J. Whitlow,G. J. Russell, NIM B 94, 277, (1994)

ERDA-ToF: analysis of MgB2 thin film with 82MeV I [1]

0 400 800 1200 1600 2000 2400 2800 3200 3600 40000

400

800

1200

1600

2000

2400

2800

3200

3600

4000

Time [

chan

nel n

o]

Energy [channel no]

10B11B O

Mg

Al

82MeV I

A l 2O 3

M gB 2 112.5o

0 50 100 150 200 250

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000 Substrate 10B 11B O Mg Al

Yield

[coun

ts]

Depth [nm]

Film

16 18 20 22 24 26 28 30 32 34 36 38

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

3786

542

On axis-Si On axis-Al2O3 Off axis; Mg cap layer Off axis; ion beam sputtered

Norm

alize

d Oxy

gen i

n MgB2 fi

lm

Tc [K]

1

• Isotope effect in MgB2 can be measured as a function of 10B/11B

• Magnesium is diffusing into the substrate• Oxygen amount critical for the quality of the film• Tc correlated with the amount of Oxygen, type of substrate, and deposition geometry[1] M. Ionescu, Y. Zhao, R. Siegele, D. D. Cohen, E. Stelcer, M. Prior, NIM B 266, 1701–1704, (2008)

NRA: Oxygen in Ta2(16O1-x+18Ox)5 thin film [1]

25 50 75 100 125 150 175 200

0

100

200

300

400

500

600

700

800

900

1000

α yie

ld [co

unts]

Channel Number

0.2 0.6 1 1.6 1.8 2.1 2.5 4

18O concentrations [at%]

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

0.0

2.0x1034.0x1036.0x1038.0x1031.0x1041.2x1041.4x1041.6x1041.8x1042.0x1042.2x104 Standard samples

Liniar Fit

α yi

eld [c

ounts

]18O concentration [at%]

y=4577 x+148R=0.99964

α

Ta2(16O1-x

18Ox)5

p 845keV

18O(p,α)15N

200nm

Ta

500 600 700 800 900 10000

10

20

30

40

50

60

70

dσ/dΩ

[mb/s

r]

Energy [keV]

18O(p,α)15N

845 keV

641 keV

[1] M. Ionescu, D. Bradshaw, R. Siegele, D. D. Cohen, O. Hawas, E. Stelcer, D. Button, D. Garton, NTA 14 Conference, 20-22 November 2005, Wellington, New Zealand

NRA: Hydrogen in thick DLC film

Γ=

σπ iNdxdEctsY

cmatN][2

]/[ 2

σΩ=

iNctsYcmatN ][]/[ 2E4

E3

E2x

γ

dxdExEE x0

00cosα−=

1H(15N,αγ)12C

dxdExEE x

x1

12 cosβ−=

E0x

At depth x:

E2

E0≥ 6.385 MeVE1x

15N

α

β

θ

E1

x

At the surface:

Energy Detectors

Ni - number of ions incident on sampleΩ − detector solid angleσ − 15N reaction cross section Γ − FWHM of resonance (1.8keV)

4He

1H12C

γ E1= 4.43 MeV

• Depth of analysis: few nm up to few microns

• Depth resolution: 5-20nm• Sensitivity: 1-100ppm

5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.51

10

100

1000

10000

Siγ Y

ield [

coun

ts/2.5

µC]

Energy 15N+ ions [MeV]

15N+

γ Detector

Si

DLC film ~700nm

• Thick DLC film grown by CVD for implants• Hydrogen content plays a role in the biologic

response [1]• Hydrogen content is higher at the surface and

decreases toward the interface• Questions remains on Hydrogen yield due to

the production of 15N- (15NH3-), the flux measurement, energy spread, etc

[1] W. J. Ma, A. J. Ruys, R. S. Mason, P. J. Martin, A. Bendavid,Z. Liu, M. Ionescu, H. Zreiqat, Biomaterials 28, 1620–1628, (2007)

Ion beam implantation and mixing

nanostructures

depth

Ion implantation

burriedlayersupersaturation

nucleationgrowth

ripeningcoalescence

timeannealing

surface

nanostructures

interface

Ion irradiation timeannealing

surface

interface mixing phase separation

• Near surface layers and interfaces can be engineered for specific properties

10K

Zn0.99Co0.01O

Zn0.99Co0.005Eu0.005OZn0.99Eu0.01O

0

0 103 2x103-103-2x103

B [Oe]

Magn

etiza

tion [

amu]

2x10-4

10-4

-10-4

-2x10-4

• ZnO thin film implanted with Eu and Co• Annealed• Magnetization measured at 300K and

10K

Conclusions• IBA nuclear techniques at ANSTO suitable for characterisation of thin films, near surface layers and interfaces

- film thickness- depth profile of light and heavy elements- defects in single crystals- 2D X-ray mapping of surfaces- radiation damage in materials- ion beam-induced chemical reactions- micro-machining

• Modification of properties by ion implant • Micro device testing (IBIC, single event upset)

Acknowledgment:D. Garton, G. Cooke; O. Evans; M. Mann; D. Lynch; E. Stelcer; P. Bond; P. Druer