1st lecture

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MENA3100

• 1st lecture
• General information, what to learn and
• some repetition of crystallography

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Student contact information
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Who is involved?

• Anette E. Gunnæs eleonora(at)fys.uio.no,
  91514080 (General, TEM, ED)
• Johan Taftø johan.tafto(at)fys.uio.no (waves
  optics, TEM, EELS)
• Ole Bjørn Karlsen obkarlsen(at)fys.uio.no (OM,
  XRD)
• Sissel Jørgensen sissel.jorgensen(at)kjemi.uio.no
  (SEM, EDS, XPS)
• Spyros Diplas spyros.diplas(at)smn.uio.no (XPS)
• Lasse Vines Lasse.vines(at)fys.uio.no (SIMS)
• Terje Finnstad terje.finnstad(at)fys.uio.no
  (SPM)
• Oddvar Dyrlie oddvar.dyrlie(at)kjemi.uio.no
  (SPM)
• Magnus Sørby magnus.sorby(at)IFE.no (ND)
• Geir Helgesen geir.helgesen(at)IFE.no (ND)

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General information

• Lectures
• Based on Microstructural characterization of
  materials by Brandon and Kaplan. SPM lecture
  based on chapter 7.8 in second edition of
  Physical methods for materials characterisation
  by Flewitt and Wild. EBSD will be based on
  separate text.
• Some parts of the Brandon and Kaplan book will be
  regarded as self study material and other parts
  will be taken out of the curriculum (chapter 7
  some sub chapters).
• Project work
• Energy related projects will be announced by the
  end of January
• Two students will work together, rank projects
  with 1st-3rd priority
• Written report, oral presentation and individual
  examination
• Counts 40 of final grade
• Laboratories
• Three groups A, B, C
• Individual reports
• All reports have to be evaluated and found ok
  before final written exam

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Laboratory groups
Laboratory work will mainly take place on
Tuesdays. The trip to IFE, Kjeller has been
rescheduled to Wednesday 13th of February!
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What to learn about

• Imaging/microscopy
• Optical
• Electron
• SEM
• TEM
• Scanning probe
• AFM
• STM
• Diffraction
• X-rays
• Electrons
• ED in TEM and EBSD in SEM
• Neutrons

• Spectroscopy
• EDS
• X-rays
• EELS
• Electrons
• XPS, AES
• Electrons (surface)
• SIMS
• Ions
• Sample preparation
• Mechanical grinding/polishing
• Chemical polishing/etching
• Ion bombardment
• Crunching etc

Different imaging modes.
Mapping of elements or chemical states of
elements.
The same basic theory for all waves.
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Probes used

• Visible light
• Optical microscopy (OM)
• X-ray
• X-ray diffraction (XD)
• X-ray photo electron spectroscopy (XPS)
• Neutron
• Neutron diffraction (ND)
• Ion
• Secondary ion mass spectrometry (SIMS)
• Cleaning and thinning samples

• Electron
• Scanning electron microscopy (SEM)
• Transmission electron microscopy (TEM)
• Electron holography (EH)
• Electron diffraction (ED)
• Electron energy loss spectroscopy (EELS)
• Energy dispersive x-ray spectroscopy (EDS)
• Auger electron spectroscopy (AES)

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Basic principles, electron probe
Electron
Auger electron or x-ray
Characteristic x-ray emitted or Auger electron
ejected after relaxation of inner state. Low
energy photons (cathodoluminescence) when
relaxation of outer stat.
Secondary electron
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Basic principles, x-ray probe
X-ray
Auger electron
Secondary x-rays
M
L
K
Characteristic x-ray emitted or Auger electron
ejected after relaxation of inner state. Low
energy photons (cathodoluminescence) when
relaxation of outer stat.
Photo electron
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Basic principles
Electrons
X-rays
Ions
(SEM)
(XD) X-rays
X-rays (EDS)
(XPS)
BSE
Ions (SIMS)
PE
AE
SE
AE
(Also used for cleaning/thinning samples)
You will learn about - the equipment -imaging -di
ffraction -the probability for different events
to happen -energy related effects -element
related effects -etc., etc., etc..
EltEo (EELS)
SE
EEo
(TEM and ED)
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Basic aspects of crystallography

• Crystallography describes and characterise the
  structure of crystals

The unit cell !
Elementary unit of volume!
- Defined by three non planar lattice vectors
a, b and c -The unit cell can also be
described by the length of the vectors a,b and c
and the angles between them (alpha, beta,
gamma).
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Unit cell

• The crystal structure is described by specifying
  a repeating element and its translational
  periodicity
• The repeating element (usually consisting of many
  atoms) is replaced by a lattice point and all
  lattice points have the same atomic environments.
• The whole lattice can be described by repeating a
  unit cell in all three dimensions. The unit cells
  are the smallest building blocks.
• A primitive unit cell has only one lattice point
  in the unit cell.

Replaces repeating element (molecule, base etc.)
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Axial systems

• The point lattices can be described by 7 axial
  systems (coordinate systems)

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Bravais lattice
The point lattices can be described by 14
different Bravais lattices
Hermann and Mauguin symboler P (primitiv) F
(face centred) I (body centred) A, B, C
(bace or end centred) R (rhombohedral)
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Hexagonal unit cell
a1a2a3 ? 120o
a2
a1
a3
(hkil) h k i 0
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Space groups

• A space group can be referred to by a number or
  the space group symbol (ex. Fm-3m is nr. 225)
• Structural data for known crystalline phases are
  available in books like Pearsons handbook of
  crystallographic data. but also electronically
  in databases like Find it.
• Pearson symbol like cF4 indicate the axial system
  (cubic), centering of the lattice (face) and
  number of atoms in the unit cell of a phase (like
  Cu).

• Crystals can be classified according to 230 space
  groups.
• Details about crystal description can be found in
  International Tables for Crystallography.
• Criteria for filling Bravais point lattice with
  atoms.
• Both paper books and online

Figur M.A. White Properties of Materials
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Lattice planes

• Miller indexing system
• Crystals are described in the axial system of
  their unit cell
• Miller indices (hkl) of a plane is found from the
  interception of the plane with the unit cell axis
  (a/h, b/k, c/l).
• The reciprocal of the interceptions are
  rationalized if necessary to avoid fraction
  numbers of (h k l) and 1/8 0
• Planes are often described by their normal
• (hkl) one single set of parallel planes
• hkl equivalent planes

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Directions

• The indices of directions (u, v and w) can be
  found from the components of the vector in the
  axial system a, b, c.
• The indices are scaled so that all are integers
  and as small as possible
• Notation
• uvw one single direction or zone axis
• ltuvwgt geometrical equivalent directions
• hkl is normal to the (hkl) plane in cubic axial
  systems

(hkl)
uhvkwl 0
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Stereographic projection

• Plots planes and directions in a 2D map

All poles in a zone are on the same great circle!!
Fig 6.5 of Klein (2002) Manual of Mineral
Science, John Wiley and Sons
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Wulff net
Fig 6.8 of Klein (2002) Manual of Mineral
Science, John Wiley and Sons
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Reciprocal vectors, planar distances

• The reciprocal lattice is defined by the vectors
  
• Planar distance (d-value) between planes hkl in
  a cubic crystal with lattice parameter a

• The normal of a plane is given by the vector
• Planar distance between the planes hkl is given
  by