Near-surface diffraction

capabilities at NECSA

TP Ntsoane

Diffraction Section

11 September 2015

OUTLINE

• Introduction• D8 Advance • Sample stage & holder types• D8 Discover• Examples: Interaction with HEI• Possible areas of collaboration• Conclude

Introduction

D8 Advance

D8 Advance D500

Comparison

• D500• NaI scintillation

• -2 goniometer

• D8 Advance• Lynx eye detector• (0 & 1 D mode)• Sample stages• - Goniometer• Sample rotation• Goebel mirror• Online status• Windows based• Variable measurement

time

NECSA-WITS Workshop

Sample stages

• Automatic sample changer• Capillary stage• XYZ stage• Small angle X-ray scattering

Automatic changer

9 sample holders (x7)Allows overnight measurementSample types: powder, liquid, thin filmsAllows sample rotation during meas.

9 sample holders (x7)Allows overnight measurementSample types: powder, liquid, thin filmsAllows sample rotation during meas.

Reflection geometryReflection geometry

Rotated by 90° Transmission geometry

Rotated by 90° Transmission geometry

Operations: Importcorundum230609 - File: Corundum230609_SH6.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70Operations: Importcorundum230609 - File: Corundum230609_SH7.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70Operations: Importcorundum230609 - File: Corundum230609_SH5.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70

Operations: Importcorundum230609 - File: Corundum230609_SH4.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70Operations: Importcorundum230609 - File: Corundum230609_SH3.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70Operations: Importcorundum230609 - File: Corundum230609_SH1.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70Operations: Importcorundum230609 - File: Corundum230609_SH2.raw - Type: 2Th/Th locked - Start: 34.600 ° - End: 35.70

Lin

(C

ou

nts

)

0

10000

20000

30000

40000

2-Theta - Scale

34.6 34.7 34.8 34.9 35.0 35.1 35.2 35.3 35.4 35.5 35.6 35.7

Superposed peaks from different multisample slots indicating variation in peak position Superposed peaks from different multisample slots indicating variation in peak position

Δ2max = 0.003°

Ok for most applications

Δ2max = 0.003°

Ok for most applications

Automatic changer con’t

XYZ stage

• Useful for localized investigation– Localized characterization– Allows large samples

Top view of XYZ stageTop view of XYZ stage

Capillary stage

• Useful for small amount of sample• Minimization of preferred orientation

Challenges: filling the capillary with powder

Challenges: filling the capillary with powder

Sample holders

Standard

Reflection = 25 mm, 40mm = 25 mm Si crystal

Domed-shape holder

Transmission = 25 mm

Capillary stage = 50 m, 1mm, 2mm, 2.5mmwall thickness = 10m

Superposed powder diffraction pattern of Cr2O3 on standard sample holder and dome-shaped and empty dome shaped sample holder.

NECSA-WITS Workshop

01-073-6214 (A) - Eskolaite - Cr2O3 - WL: 1.5406 - Rhombo.H.axes - a 4.96070 - b 4.96070 - c 13.59900 - alpha 90.000 - beta 90.000 - gamma 120.000 - R-3c (167) - PrimitiveOperations: ImportY + 3.0 mm - File: Cr2O3a_domed sample holder.raw - Type: 2Th/Th locked - Start: 20.000 ° - End: 140.005 ° - Step: 0.020 ° - Step time: 151.2 s - Anode: Cu - WL1: 1.5406 - WL2: 1.54439 - Generator kV: 40 kV - GeOperations: ImportFile: Cr2O3a.raw - Type: 2Th/Th locked - Start: 20.000 ° - End: 140.005 ° - Step: 0.020 ° - Step time: 75.6 s - Anode: Cu - WL1: 1.5406 - WL2: 1.54439 - Generator kV: 40 kV - Generator mA: 40 mA - Creation: 2009/0

Lin

(C

ou

nts

)

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

12000

13000

14000

2-Theta - Scale

20 30 40 50 60 70 80 90 100 110 120 130 140

Possible investigations

● Grazing angle investigations: inc < 1

Thin films

Near-surface modifications

● Analysis of radioactive & environmentally sensitive samples

D8 Discover

– 2D detector Vantec500– Laser & Video align– Eulerian cradle– 0.8mm collimator

Applications

Residual strain and stress investigationTexture analysisMicro Powder diffraction (Phase identification)

Basic principle

sin2

0

211

= 0º = 10º = 20º = 30º = 40º = 50º = 60º = 70º = 80º = 89.7º

Q211

2211

I

222 22 2222 2

d211

C

2

1 11 22

1s

2sC

Q211Q211

Q211Q211

Q211Q211

Q211Q211

Q211Q211

Q211Q211

Q211Q211

Q211Q211

Q211Q211

Q211Q211Scattering plane

compressive stress

Interaction HEI

0 50 100 150 200 250 300 350 400600

800

1000

1200

1400

1600

1800

no

rmal

str

ess

(MP

a)

thickness (nm)

11

22

Thin films

Ms P. Mudau, Univ. of Johannesburg

Interaction with HEI

Dr. N. Janse van Rensburg, Univ. of Johannesburg

Grit-blasted Ti alloy cylinder

Thermal sprayed Coating

20 30 40 50 60 70 80-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

11

Zn conc %

Zn- Sn

Ms H. Mathabatha, TUT

Micro Diffraction

Phase identification in Friction Spot Stir Weld

00-024-0003 (C) - Aluminum Copper - Cu9Al4 - WL: 1.54184 - Cubic - a 8.70270 - b 8.70270 - c 8.70270 - alpha 90.000 - beta 90.000 - gamma 90.000 - P-43m (215) - Primitive

01-071-5027 (*) - Khatyrkite - CuAl2 - WL: 1.54184 - Tetragonal - a 6.07000 - b 6.07000 - c 4.89000 - alpha 90.000 - beta 90.000 - gamma 90.000 - I4/mcm (140) - Body-centered

01-073-2762 (I) - Copper Aluminum - Cu3Al - WL: 1.54184 - Cubic - a 5.82000 - b 5.82000 - c 5.82000 - alpha 90.000 - beta 90.000 - gamma 90.000 - Fm-3m (225) - Face-centered

01-071-4611 (A) - Copper, syn - Cu - WL: 1.54184 - Cubic - a 3.62700 - b 3.62700 - c 3.62700 - alpha 90.000 - beta 90.000 - gamma 90.000 - Fm-3m (225) - Face-centered

01-071-4622 (A) - Aluminum - Al - WL: 1.54184 - Cubic - a 4.05000 - b 4.05000 - c 4.05000 - alpha 90.000 - beta 90.000 - gamma 90.000 - Fm-3m (225) - Face-centered

Operations: Enh. Background 2.570,1.000 | Import

Y + 0.1 mm - File: FSSW 11 Al-Cu pt1_working range.out - Type: 2Th alone - Start: 27.400 ° - End: 116.600 ° - Step: 0.100 ° - Step time: 210. s - Anode: Cu - WL1: 1.54184 - WL2: n.a. - Generator kV: 20 kV - Generat

Lin

(C

ou

nts

)

0

100

200

300

400

500

600

700

800

900

1000

2-Theta - Scale

28 30 40 50 60 70 80 90 100 110

Mr P. Mubiayi, UJ

0.0 0.5 1.0 1.5 2.0-350

-300

-250

-200

-150

-100

-50

0

50

100

150

200

P

rinci

pal s

tres

s / M

Pa

fatigue

I

II

Mr M. Vhareta, WITS

Influence of fatigue on residual stress

Influence of fatigue on residual stress

Prof R. Knutsen, Univ. of Cape Town

Pole figures of rolled AluminiumSoftware: Multex

Texture analysis

Possible areas of collaboration

Near-surface characterization of layered structures modified surfaces i.e. grit-blasting, polishing etc Irradiated surfaces Engineering components

Thin film investigation Micro-diffraction for localized investigation

For more information: Tshepo Ntsoane tshepo.ntsoane@necsa.co.zaZeldah Sentsho zeldah.sentsho@necsa.co.zaAndrew Venter andrew.venter@necsa.co.za

African Light Source Conference and WorkshopEuropean Synchrotron Radiation Facility, Grenoble France16th – 20th November 2015

http://www.saip.org.za/AfLS2015/.

THANK YOU