alla arakcheeva basic introduction x-ray techniques

Alla Arakcheeva

Basic Introduction

X-ray techniques

• X-rays is the most important discovery in recent history

• Who have enlightened our world?

• Sources of X-rays

• Interaction of X-rays and matter

• Methods based on X-ray spectroscopy (XRS)

• Methods based on X-ray diffractometry (XRD)

• Using synchrotron radiation

• Synchrotron or home laboratory?

X-ray techniques. Basis introduction

The X-ray has been voted as the most important discovery in recent history

… by 50’000 participants in a British Science Museum poll,

which had been carried out in 2009

1. The X-ray machine

2. Penicillin

3. The DNA double helix

…• “X-rays have radically changed the way we see

and understand our world” • “X-rays allowed to look inside without any damage

of solids and to see a human body without any operation”

Who have enlightened our world?

Beginners • 1895 Wilhelm Konrad Roentgen discovered and described properties of new rays, which he

called X-rays

He held a demonstration with his first X-Ray pictures, along with one of his wife's hand.

1901 The First Nobel Prize for Physics

Beginners• 1899 H. Haga and C. Wind discovered the X-Rays diffraction by a slit

The X-rays are electromagnetic waves with l ~ 1 Å


Beginners• 1904 Charles Barkla discovered the secondary (characteristic) X-ray radiation of

elements, which depends on their atomic weight

Decelerated or «braking» or «white» X-ray radiation

K

1917Nobel Prize in Physics


Beginners• 1912 Max von Laue discovered diffraction of X-rays by crystals

1914Nobel Prize in Physics{

Laue’s equations:

S . a = n1 (integer)S . b = n2 (integer)S . c = n3 (integer)

S - scattering vectora, b, c - lattice vectors


Beginners• 1912 Sir William Lawrence Bragg derived Bragg's Law


Beginners• 1915 Sir William Henry Bragg and William Lawrence Bragg jointly received Nobel Prize in Physics

"for their services in the analysis of crystal structure by means of X-rays”

Start of X-ray crystallography:C (diamond), NaCl, KCl, KBr, KI, CF2, ZnS, FeS2, CaCO3, …


26 Nobel Prizes were awarded for achievements related to X-ray techniques

• … • 2009 ChemistryV. Ramakrishnan, T.A. Steitz, A.E. YonathStudies of the structure and function of the ribosome• 2011 ChemistryDaniel Shechtman"for the discovery of quasicrystals"

Ribosome

X-rays

• X-rays are electromagnetic waves, l ~ 10-11 – 10-8 m• X-rays appear when electrons are accelerating or decelerating• X-rays interact with electrons

Sources of X-rays

1. X-ray tubes operate in laboratory devices

Scheme

Thermo-emitted electrons

Accelerating voltage Ua ~ 50kV

Water cooling system

X-rays

Voltage cathode heating

2. Synchrotron radiation

The X-ray flux is 104 – 106 times more intense than in the X-ray tube

Sources of X-rays

European Synchrotron radiation Facility (ESRF), Grenoble:Energy of one beam 6 GeV

Accelerator of electrons

Beam lines

Sources of X-rays

Circumference 844 m

http://youtu.be/eLVeoCZOy-M

A single beam line


Sources of X-rays

A single beam line

Experimental facilities

A management team


Sources of X-rays


Sources of X-rays

41 beam-lines are managed by 19 countries


Sources of X-rays

Inside of a beam line


Sources of X-rays

Come back in 15 minutes

Elastic scatering

Basis of X-ray analysisInteraction of X-rays and matter

Inelastic interactions

Diffraction

Methods based on X-ray diffractmetry (XRD)

Methods based on X-ray spectrometry (XRS)

Method based on X-ray spectroscopy(XRS)

• X-ray tomography• Extended X-ray absorption spectrometry (EXAFS)

• X-ray fluorescence spectroscopy

Method Results Areas of application


Chemical analysis

Tiny sample or tiny area under study

Art & Archeology, Materials, Geology, Biomedicine, Environmental science

How it works at synchrotron (ESRF, Grenoble)

Scheme


Method based on X-ray spectroscopy(XRS)



• X-ray tomography - Absorption - Fluorescence

3D maping of - Morphology - Chemistry

- Construction materials - Microelectronics - Nuclear materials - Soft materials (polymers, cells, bone)

Silicon chip stacking in microelectronics

3µm

How it works (ESRF, Grenoble)

Scheme


Method based on the X-ray spectroscopy(XRS)



• Extended X-ray absorption spectrometry

EXAFS – Extended X-ray Absorption Fine Structure

Local atomic enviroment

- Disordered matter (amorphous, liquids) - Surfaces, interfaces - Multiphase systems - HeterostructuresCatalytic system, alloys, ceramics, corrosions, semiconductors, …

Local structure vs Oxygen Storage Capacity in mixed oxidesNagai et. Al. Catalysis Today (2002)

How it works (ESRF, Grenoble)

Diffraction

Metod based on X-ray diffraction (XRD)

• X-ray topography• Small and Wide-Angle Scattering (SAXS/WAXS)

• Single crystal and powder XRD

Method Results Areas of application• Single crystal XRD

- Symmetry and lattice constants - Molecular and/or Atomic structure - Chemical bonds - Refined chemical composition - Electron density distribution

Chemical crystallography of - inorganics - organometalics - small and macro molecules inPhysics, Chemistry, Life Sciences, Mineralogy, Materials, Metallurgy

V. Ramakrishnan, T. A. Steitz, A. E. Yonath

Nobel Prize in 2009W. H. Bragg and W. L. Bragg

Nobel Prize in 1915NaCl Ribosome

The universal method for discovery !

A new second-order nonlinear optical material 4-bromo-4’nitrobenzylidene aniline (BNBA), C13H9BrN2O2

Typical studyConfirmation of expected structure of a new small molecule compound

Single crystal XRD

Single crystal18’234 measured reflections; T = 173 K

4-bromo-4’nitrobenzylidene aniline (BNBA),A new second-order nonlinear optical material


Single crystal XRD


Single crystal XRD

• Expected result: monoclinic crystallographic system• Unexpected Result: Non-traditional, (3+1)D symmetry – A2(a0g)0

Satellites Hhklm = ha* + kb* + lc* + mq (de Wolff, P.M. , 1974)

h

l

H4000

mtw

H4001

q

Bragg’s reflections

Hhkl = ha* + kb* + lc*(W. L. Bragg, 1912)

• Expected result: Structure of the small molecule



Single crystal XRD

• Expected result: H-bonds between molecules• Unexpected Result: Aperiodic distribution of the H-bonds



Single crystal XRD

• Unexpected Result: Splitting of molecule at 293 K



Single crystal XRD

Method Results Areas of application• Powder XRD

o For single phase material - Symmetry and lattice constants - Atomic ordering - Chemical bonds o For poly-phasic Material - Phase composition - Grain size - Micro-strain distribution

Chemical crystallography of - inorganics - organometalics - small molecules inPhysics, Chemistry, Life Sciences, Mineralogy, Materials, Metallurgy

Universal method for routine work

Typical tasks Degree of crystallinity

Tim

e of

ann

ealin

g

Diffraction (scattering) angle 2q

0 180

Powder XRD

Typical tasks

Phase identification

> 600’000 reference materials are currently listed in the Powder Diffraction File Database

Identification of (NH4)6(NiMo9O32).6H2OExperimental profileandReferred lines from PDF 77-1734

Powder XRD

Typical tasks Crystal structure determination and refinement

Bi (known), BiOCuS (known), BiCu5O3S (unknown before) !

BiCu5O3S BiOCuS

Powder XRD

Typical tasks Phase analysis quantitative & qualitative

Paint sample from ancient Ethiopian icons

1

2

1

2

Powder XRD

KSm(MoO4)2

Isotropic micro-strain line broadening boadening

Anisotropic micro-strain line broadening

The anisotropic micro-strain distribution is the origin of the anisotropic line broadening

Typical tasks Anisotropic micro-strain distribution

Powder XRD

Diffraction

Methods based on X-ray diffraction (XRD)



X-ray diffraction imaging or X-ray-topographyObjects• nearly perfect crystals


• X-ray-topography or X-ray diffraction imaging

• Imaging defects - Dislocations- Stacking faults- Scratches- Inclusions

Nearly perfect crystals - Microelectronics - optoelectronics - Photovoltaic silicon - Optics - …

How it works at ESRF (Grenoble)

Diffraction

Methods based on X-ray diffraction (XRD)



Method Results Areas of application• Small and Wide Angle Scattering (SAXS / WAXS)

• Micro- and nano-structure and phase behavior of multi-components systems - Texture - Preferable orientations - Degree of crystallinity

Soft condensed matter - polymers, fibers Nanocrystalline structures - biological objects - films, surfaces, interfaces - In-situ studies

How it works Solid

Submelted

Recrystallized

Randomly aligned domains

Preferentially aligned domains

µm and nm scales of analyzed objectScattering angles: 0.1 – 10o

Micro / nano X-ray diffraction using synchrotron radiation (ESRF)

Specific features • Non-destructive techniques• High flux X-ray energy: typical 8-24 keV up to 100 keV at HE beamline• Focused beam (100 nm)• Scanning diffraction with spatial resolution• Micro/nano size of analyzed object (down to 100 nm)

Applications• Single polymer fiber diffraction• Scanning diffraction of polymer films• Grazing incidence micro-diffraction on surfaces• Chemical micro-crystallography• Structure of Individual powder grain

http://youtu.be/LYZo527Cgdg

http://youtu.be/LYZo527Cgdg

Synchrotron or home laboratory?

• General and average characteristics

Home Laboratory

• Lower overall cost of a study• Ease accessibility• Easy to use• Quick average characterization of a large volume (down to µm scale)

• Advanced and precise study

Use laboratory devicesif you are going- To confirm

traditional views - To add a new item

to a well known list

Use synchrotron radiationif you are ready - To explore

new fields- To reconsider

some theories

Synchrotron laboratory

• Higher resolution• Higher flux• Quick counting times in experiments• Precise characterization of a local area (down to nano scale)

Thank you for your attention !

alla arakcheeva basic introduction x-ray techniques

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