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16.02.2010 Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010 Magnus H. Sørby

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Page 1: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Powder Neutron Diffraction - an introduction

Neutron scattering course – February 16, 2010

Magnus H. Sørby

Page 2: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Scope

• The advantages of neutrons vs. X-rays

• Examples of neutron diffraction studies

• Neutron diffraction at IFE

Page 3: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

The glory of neutrons• There is no systematic correlation between

atomic number and the scattering length.• Can get information about light and heavy

elements simultaneously.Can distinguish neighboring elements in the

periodic table.

• The neutron interacts weakly with matter.Complicated sample environment is possible.Large samples can be studied.Scattering from bulk; not just the surface.

• The neutron has a magnetic moment.Can study magnetic ordering.

Page 4: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Metal hydrides• Materials that contain chemical bonding

between metal- and hydrogen atoms.

Light and heavy elements

4 kg H2

L. Schlapbach, A. Zuttel Nature 414 (2001) 353-358

300 kg

Mg2 NiH4 LaNi5 H6 Liquid H2 H2 gas (200 bar)

M(s) + x/2 H2(g) MHx(s) + energy

Page 5: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Alanates AlH

AlH4-

Al

H

AlH63-

3 NaAlH4 Na3 AlH6 + 2 Al + 3 H2 3.7wt% ~120C

Na3 AlH6 3 NaH + Al + 3/2 H2 1.9wt% ~180C

NaH Na + ½ H2 1.9wt% 425C

B. Bogdanovic, J. Alloys Comp. 253-254 (1997) 1-9.

5.6 wt%

TiCl3

TiCl3

Light and heavy elements

Page 6: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Li3 AlD6 seen by neutrons

ac

Li3 AlD6 seen by X-rays

PUS - high resolution diffractometer

The JEEPII reactor

Crystal structure of alanates

Al

D

Light and heavy elements

NaAlH4Na3 AlH6LiAlH4-LiAlH4Li3 AlH6KAlH4Mg(AlH4 )2Sr2 AlH7BaAlH5Ba2 AlH7Na2 LiAlH6K2 NaAlH6LiMg(AlH4 )2LiMgAlH6Ca(AlD4 )2CaAlD5

Page 7: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

NaAlD4

Na2 LiAlH6

LiAlD4

KAlD4

LiMgAlD6

K2 NaAlD6

-LiAlD4

LiMg(AlD4 )3

Li3 AlD6

Mg(AlH4 )2

Crystal structure of alanates

Diversity• Symmetries ranging from cubic to monoclinic• A variety of local configuration.

ab

c a

bc

ab

c

LiAlD4CN(Li-D) = 5P21 /c [1]

NaAlD4CN(Na-D) = 8I41 /a [2]

KAlD4CN(K-D) = 10Pnma [3]

[1] B. C. Hauback, et al., J. Alloys Comp. 346 (2002) 184-189.[2] B. C. Hauback, et al., J. Alloys Comp. 358 (2003) 142-145.[3] B. C. Hauback, et al., J. Alloys Comp. 394 (2005) 35-38.

Light and heavy elements

Page 8: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

NaAlD4

Na2 LiAlH6

LiAlD4

KAlD4

LiMgAlD6

K2 NaAlD6

-LiAlD4

LiMg(AlD4 )3

Li3 AlD6

Mg(AlH4 )2

Crystal structure of alanates

Diversity• Symmetries ranging from cubic to monoclinic• A variety of local configuration

Similarities• Average Al-D: 1.60-1.64 Å (AlD4

-) 1.74-1.80 Å (AlD6

3-)

Na2 LiAlD6

Al-D = 1.760(1) Å, a = 7.385 Å [1]

K2 NaAlH6

Al-H = 1.759(1) Å, a = 8.118 Å [2]

[1] H. W. Brinks, et al., J. Alloys Comp. 392 (2005) 27-30.[2] M. H. Sørby, et al., J. Alloys Comp. 415 (2006) 284-287.

Fm3m

Light and heavy elements

Page 9: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

a

b

c

NaAlD4

Na2 LiAlH6

LiAlD4

KAlD4

LiMgAlD6

K2 NaAlD6

-LiAlD4

LiMg(AlD4 )3

Li3 AlD6

Mg(AlH4 )2

Crystal structure of alanates

R3 a = 8.071 Å c = 9.513 Å

Li3 AlD6pseudo-bcc packing of AlD6

3-

Li+ in ½ of tetrahedral sites

Diversity• Symmetries ranging from cubic to monoclinic• A variety of local configuration

Similarities• Average Al-D: 1.60-1.64 Å (AlD4

-) 1.74-1.80 Å (AlD6

3-)• Anion sublattice often related to simple

sphere packing structures.

Light and heavy elements

Page 10: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

The glory of neutrons• There is no systematic correlation between

atomic number and the scattering length.• Can get information about light and heavy

elements simultaneously.• Can distinguish neighboring elements in the

periodic table.• The neutron interacts weakly with matter.

Complicated sample environment is possible.Large samples can be studied.Scattering from bulk; not just the surface.

• The neutron has a magnetic moment.Can study magnetic ordering.

Page 11: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Alloys-Mn: Cubic, complex structure, a = 6.31 Å,

Z = 20

Neighboring elements

Mn(1)12 Mn(2)8What happens if 40% of the Mn is substituted with Co?

a

Page 12: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Alloys-Mn: Cubic, complex structure, a = 6.31 Å,

Z = 20

Neighboring elements

[Mn0.6 Co0.4 ](1)12 [Mn0.6 Co0.4 ](2)8What happens if 40% of the Mn is substituted with Co?

a

Page 13: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Alloys-Mn: Cubic, complex structure, a = 6.31 Å,

Z = 20

Neighboring elements

What happens if 40% of the Mn is substituted with Co?

Mn(1)12 Co(2)8a

Page 14: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

AlloysWhich model is right for Mn0.6 Co0,4 ?

Neighboring elements

Random Co distribution

Ordered Co distributionX-rays:Z(Mn)=25Z(Co)=27

Page 15: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Alloys

Neighboring elements

Random Co distribution

Ordered Co distributionX-rays:Z(Mn)=25Z(Co)=27

Neutrons:b(Mn)=-0.373b(Co)=+0.249

Which model is right for Mn0.6 Co0.4 ?

Random Co distribution

Ordered Co distribution

Page 16: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Alloys

Neighboring elements

Which model is right for Mn0.6 Co0.4 ?

Co selectively occupy the 8-fold position!

Page 17: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

The glory of neutrons• There is no systematic correlation between

atomic number and the scattering length.• Can get information about light and heavy

elements simultaneously.• Can distinguish neighboring elements in the

periodic table.

• The neutron interacts weakly with matter.• Complicated sample environment is possible.Large samples can be studied.Scattering from bulk; not just the surface.

• The neutron has a magnetic moment.Can study magnetic ordering.

Page 18: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Sample environment

Penetration depth

• Neutrons can penetrate several millimeters of materials like aluminium and steel.

Sample container (Inconel super-alloy) rated to 3000 bar and 600oC.

Page 19: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Sample environment• Neutrons can penetrate several millimeters

of materials like aluminium and steel.

Furnace

Penetration depth

Page 20: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Sample environment• Neutrons can penetrate several millimeters

of materials like aluminium and steel.

Cryostat

Penetration depth

Page 21: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

The glory of neutrons• There is no systematic correlation between

atomic number and the scattering length.• Can get information about light and heavy

elements simultaneously.• Can distinguish neighboring elements in the

periodic table.

• The neutron interacts weakly with matter.• Complicated sample environment is possible.• Large samples can be studied.Scattering from bulk; not just the surface.

• The neutron has a magnetic moment.Can study magnetic ordering.

Page 22: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Study of large samples

Penetration depth

• How did the machining of the hole influence the material?

Page 23: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Study of large samples

Penetration depth

Page 24: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Study of large samples

Penetration depth

3D residual stress-field can be mapped in a non-destructive way!

Loading a sample at the NRSF2 instrument at Oak Ridge National Lab (US)

Page 25: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

The glory of neutrons• There is no systematic correlation between

atomic number and the scattering length.• Can get information about light and heavy

elements simultaneously.• Can distinguish neighboring elements in the

periodic table.• The neutron interacts weakly with matter.

• Complicated sample environment is possible.• Large samples can be studied.• Easy interpreations of scattering intensities

are easily.• The neutron has a magnetic moment.

Can study magnetic ordering.

Page 26: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Scattering intensity2

)( 22

)( 22 i

lzkyhxii

i

KriiK

iiii ebebFI

• Can (usually) neglect effects of multiple scattering, extinction and absorption.

Page 27: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

The glory of neutrons• There is no systematic correlation between

atomic number and the scattering length.• Can get information about light and heavy

elements simultaneously.• Can distinguish neighboring elements in the

periodic table.• The neutron interacts weakly with matter.

• Complicated sample environment is possible.• Large samples can be studied.• Easy interpreations of scattering intensities are

easily.• The neutron has a magnetic moment.

• Can study magnetic ordering.

Page 28: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Magnetic neutron scattering• The neutron has a

magnetic moment.• This will interact with the

magnetic moment of atoms with unpaired electrons.

Magnetic scattering

unit scattering vector, K magnetic spin

direction, Mincident beam

diffracted beam

i

lzkyhxiiihklmagnetic

iiiefmF )( 2,

MKm

MKm

mMMKKm

,1

,0

sin,)(

|| 2

,2

,2

hklmagnetichklnuclhklhkl FFFI

Page 29: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Magnetic neutron scattering

Magnetic scattering

5 10 15 20 25 30 35

0

50

100

150

200

250

300

350

400

450

Inte

nsity

(arb

. uni

ts)

2 (deg.)

100

111

110Nuclear scattering

Page 30: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Magnetic neutron scattering

Magnetic scattering

5 10 15 20 25 30 35

0

50

100

150

200

250

300

350

400

450

Inte

nsity

(arb

. uni

ts)

2 (deg.)Ferromagnetic

100

111

110Nuclear scatteringMagn. scatteringTotal scattering

Page 31: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Magnetic neutron scattering

Magnetic scattering

5 10 15 20 25 30 35

0

50

100

150

200

250

300

350

400

450

Inte

nsity

(arb

. uni

ts)

2 (deg.)Antiferromagnetic

Nuclear scatteringMagn. scatteringTotal scattering

100

111

110

½00 ½10 ½11

Page 32: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

PUS – a high resolution diffractometer

Neutron diffraction at IFE

• In operation since 1997.

Page 33: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

PUS – a high resolution diffractometer

Neutron diffraction at IFE

• In operation since 1997.

Soller collimator (from Risø). 15’, 30’ and “open” (60’)

Page 34: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

PUS – a high resolution diffractometer

Neutron diffraction at IFE

• In operation since 1997.

Vertically focusing Cu monochromator (from Risø).311, 511 or 711 reflection plane can be used

= 0.75-2.60 Å

Page 35: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

PUS – a high resolution diffractometer

Neutron diffraction at IFE

• In operation since 1997.

Sample temperature: 8 – 1200KGas pressures up to 8 bar (soon 100 bar)

Page 36: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

PUS – a high resolution diffractometer

Neutron diffraction at IFE

• In operation since 1997.

Oscillating radial collimators (MURR).

Page 37: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

PUS – a high resolution diffractometer

Neutron diffraction at IFE

• In operation since 1997.

2 detector banks with 7 vertically stacked position sensitive detectors in each. Each bank cover 20o scattering angle.

Page 38: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

R2D2- a second-hand powder diffractometer

SANS

Staircase

Cold Moderator

JEEP II

To Air

Lock 12

3

4

5

6

7

89

10

10 m

R2D2

TOF

PUS 1

DIFF

Reflectometer

Nye instrumenter

Page 39: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

R2D2

• moved from Risø (TAS3) to Studsvik in 2000.

• moved from Studsvik to Kjeller in 2005.

• resolution as PUS.• ... but only 1/6 of the intensity.• operational in a few months

New instruments

- a second-hand powder diffractometer

Page 40: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

ODIN- a brand new powder diffractometer

SANS

ODIN

Staircase

Cold Moderator

JEEP II

To Air

Lock 12

3

4

5

6

7

89

10

10 m

R2D2

PUS 1

DIFF

Reflectometer

New instruments

Page 41: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

ODIN

• Optimized DIffractometer for Neutrons

• All aspects of the design is optimized by Monte Carlo simulations.

• 3.5 times higher intensity at slightly better resolution than PUS.

• Or 15 times higher intensity at lower resolution.

New instruments

- a brand new powder diffractometer

Page 42: Powder Neutron Diffraction - Universitetet i oslo · Powder Neutron Diffraction - an introduction Neutron scattering course – February 16, 2010. Magnus H. Sørby. 16.02.2010. Scope

16.02.2010

Conclusion• Powder Neutron Diffraction give unique

structural information about:• Compounds that contain both light and heavy

elements.• Compounds that contain elements of similar weight.• Samples under high pressure and extreme

temperatures.• Large samples like machine parts.• Magnetic materials.