- International school on fundamental crystallography and electron crystallography
- Scientific Program
- International Program Committee and lecturers
- List of praticipants
- Registration and News
- Lectures
Organized by the Bulgarian Crystallographic
Society,
Institute
of Optical Materials and Technologies (IOMT) “Academician Jordan Malinovski”
and the
IUCr Commission on Mathematical and Theoretical Crystallography
International Autumn School on
Fundamental and Electron Crystallography (IASFEC)
8-13 October 2017 , Sofia, Bulgaria
Timetable
Lectures: 9.30- 13.30
Coffee break:
10.15-10.45
Lunch break: 13.30-15.00
Afternoon session (3.5
hours)
Exercises: 15.00 -18.30
Coffee break: 16.30-17.00
Necessary background (assumed achieved by all participants)
- Basic matrix algebra (matrix multiplication, calculation of determinant and trace)
- Interaction of radiation with matter.
- Elementary physics of scattering and diffraction. Fourier transform, atomic scattering factor and structure factor.
- Reciprocal lattice
- Bragg's law and Ewald's sphere.
Introduction to group theory: symmetry, symmetry groups,
point groups, lattices, unit cells, lattices planes, Miller indices, forms,
zones, zone axes, stereographic projections, metric tensor and
crystallographic calculations, subgroups, group – subgroup relations, change
of basis from group to subgroup,symmetry operations with a glide component,
effect of screw axes, Gjonnes-Moodie lines;
Integral, zonal and
serial diffraction conditions, indexing of ED patterns, calculation and
simulation of SAED pattern for a given compound, reconstruction of the unit
cell from SAED along different zone axes, analysis of CBED pattern,
differences between the symmetry information from SAED and CBED,
determination of point groups and space group from ED patterns, domains,
effect of twinning, twin index, unit cell of the twin lattice, determination
of space groups from ED patterns;
Scientific Program
|
Day 1: 08 October 2017, Sunday |
|
|
morning |
Arrival, registration and accommodation |
|
|
Lecturer: prof. Mois Aroyo |
|
13:30 – 18:00 |
Basic matrix
algebra (matrix multiplication, calculation of determinant and
trace) |
|
Day 2: 09 October 2017, Monday |
|
|
9:15 – 9:30 |
Opening of the School (Dr. Daniela Karashanova) |
|
|
Lecturers: prof. MoisAroyo, prof. Massimo Nespolo |
|
9:30 – 11:00 |
Introduction to group theory:
the
notion of symmetry and symmetry groups.
Lattices and unit cells.
Crystallographic
symmetry in two dimensions |
|
11:00 – 11:30 |
Coffee break |
|
11:30 – 13:30 |
Crystallographic symmetry in three
dimensions: Bravais lattices, point groups, holohedries and
merohedries, point groups; Hermann-Mauguin symbols for point groups. |
|
13:30 – 15:00 |
Lunch |
|
15:00 – 16:30 |
Lattice planes, Miller indices and Bravais-Miller
indices. Forms, zones and zone axes.
Choice of the zones to look at in ED for the
different crystal systems.
Introduction to the stereographic projection
and exercises on the stereographic projection
to build crystallographic point groups. |
|
16:30 – 17:00 |
Coffee break |
|
17:00 – 18:30 |
Subgroups of point groups |
|
19:00 – 20:00 |
Dinner |
|
Day 3: 10 October 2017, Tuesday |
|
|
|
Lecturers: prof.
MassimoNespolo, prof.Mois Aroyo |
|
9:30 – 11:00 |
Metric tensor and crystallographic calculations: norm
of a vector, angle between vectors, change of basis. |
|
11:00 – 11:30 |
Coffee break |
|
11:30 – 13:30 |
Symmetry operations with a screw or glide component.
From point to space groups. |
|
13:30 – 15:00 |
Lunch |
|
15:00 – 16:30 |
Examples and exercises on space group diagrams.
Projections of space groups and their two-dimensional
symmetry. |
|
16:30 – 17:00 |
Coffee break |
|
17:00 – 18:30 |
Group-subgroup relations. Klassengleiche,
translationengleiche, isomorphic subgroups. Change of basis from
group to subgroup.
Definition and basic features of parent and
daughter phases.
Integral, zonal and serial diffraction conditions.
Diffraction symbol and possible space groups
corresponding to it. |
|
19:00 – 20:00 |
Dinner |
|
Day 4: 11 October
2017, Wednesday |
|
|
|
Lecturers and guidance: Dr. Daniela Karashanova, Dr. Diana Nihtianova, Dr. Bogdan Ranguelov,
Dr. MihailTarassov |
|
09 :30
|
Work
in groups at
rotational principle |
|
1/2 day |
Transmission Electron
Microscopy (TEM) laboratory visit |
|
|
basics of TEM |
|
|
sample preparation for TEM |
|
|
experimental SAED and CBED patterns caption |
|
1/2 day |
Scanning electron microscopy (SEM) – laboratory visit |
|
|
basics of SEM |
|
|
sample preparation
for SEM |
|
|
Electron Back Scattered Diffraction (EBSD) |
|
11:00 – 11:30
16:00 – 16:30 |
Coffee break and exchange of groups
Coffee break and Poster session |
|
13:30 – 15:00 |
Lunch |
|
15:00 – 17:00 |
Poster session |
|
19:00 – 20:00 |
Dinner |
|
Day
5: 12 October 2017,
Thursday |
|
|
|
Lecturer: prof. Joke Hadermann |
|
9:30 – 11:00 |
Indexing of an ED pattern.
Calculation / simulation of a SAED pattern
for a given compound (from cell parameters and zone axis).
Reconstruction of the unit cell from SAED
along different zone axes. |
|
11:00 – 11:30 |
Coffee break |
|
11:30 – 13:30 |
Connection of the symmetry in real space to
that of the ED pattern.
Analysis of the information one can obtain
from CBED. |
|
13:30 – 15:00 |
Lunch |
|
15:00 – 16:30 |
Differences between the symmetry
information from SAED (addition of inversion centre, can't
distinguish m or 2) and CBED (can distinguish all point symmetry
elements).
Exercises on experimental SAED and CBED
patterns |
|
16:30 – 17:00 |
Coffee break |
|
17:00 – 18:30 |
From superlattices (subcells) in ED to
sublattices (supercells) in real space.
Determination of point groups and space
groups from ED patterns. |
|
19:30 – 22:30 |
Official Dinner |
|
Day
6: 13 October 2017,
Friday |
|
|
|
Lecturer: prof.
Massimo Nespolo |
|
9:30 – 11:00 |
Domains (twins, antiphase domains); effect
of twinning on the diffraction pattern.
Calculation of twin index, obliquity, unit
cell of the twin lattice.
Splitting of reflections following a phase
transition to a lower lattice system. |
|
11:00 – 11:30 |
Coffee break |
|
|
Lecturer: prof. Joke Hadermann |
|
11:30 – 13:30 |
Effect of the presence of symmetry
operations with a glide component on ED patterns, effect of screw
axes, Gjonnes-Moodie lines
Determination of space groups from ED
patterns |
|
13:30 – 15:00 |
Lunch |
|
15:00 – 16:30 |
Dynamical effects of the multiple
diffractions and their effect on the reflection conditions and
expected equivalence of reflections.
Partial reconstruction of the space group
symmetry from atomic resolution images (projection of space groups,
effects of misorientation). |
|
16:30 – 17:00 |
Coffee break |
|
17:00 – 18:30 |
Short introduction on the possibilities of
extracting and using the reflections on ED patterns in a
quantitative manner to solve structures ab initio and to refine
structures.
Exercises on the determination of space
group from electron diffraction patterns. |
|
18:30 – 18:45 |
Concluding remarks (Dr. Daniela Karashanova) |
|
19:00 – 21:00 |
Farewell dinner |
Necessary background (assumed achieved by all participants):
•
Interaction
of radiation with matter.
•
Elementary physics of scattering and diffraction.
Fourier transform, atomic scattering factor and structure
factor.
•
Reciprocal lattice
•
Bragg's law and Ewald's sphere.
The Organizers of the International School on Fundamental and Electron Crystallography will observ the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to such factors as citizenship, religion, creed, political stance, ethnic origin, race, colour, language, age or sex, in accordance with the Statutes of the International Council for Science. At this school no barrier will exist which would prevent the participation of bona fide scientists.
Registration
Organised by the Bulgarian Crystallographic Association, the IUCr Commission on Mathematical and Theoretical Crystallography and sponsored by the "International Union of Crystallography" and the European Crystallographic Association
