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The "2nd International School
on Aperiodic Crystals" took place at the University of Bayreuth in
Bayreuth, Germany, from 7 through 12 April 2013. The School has been
organized by the Commission on Aperiodic Crystals of the International
Union of Cystallography (IUCr),
with the support from the French National Center for Scientific Research
(CNRS, "formation permanente"), the
European C-MAC and the German Crystallographic Association (DGK). Local organisation was by Marc de Boissieu
(Grenoble), Andreas Schönleber (Bayreuth) and
Sander van Smaalen (Bayreuth). The University of
Bayreuth provided several seminar rooms for lectures, tutorials and the
poster session. The objectives of the School were to provide an overview of
aperiodic order in crystals, of the basics of the superspace
description of both modulated structures and quasicrystals,
of physical properties and crystal chemical understanding of aperiodic
crystals, as well as a working knowledge of structural analysis of
aperiodic crystals.
The "2nd International School
on Aperiodic Crystals" was attended by 50 participants, including 10
invited lecturers, 33
young scientists (mainly PhD students) and 7 senior scientists. The participants came from 14 countries:
Belgium (1), Canada (1), Czech Republic (3), France (7), Germany (19),
Israel (1), Japan (1), Poland (4), Slovakia (4), Slovenia (2), Sweden (2),
Switzerland (1), United Kingdom (3), U.S.A. (1).
The participation of five PhD students (from Sweden, France, 2´Poland and Slovenia, respectively) has been
made possible through a Young Scientist Award by the IUCr
of monetary value of USD 600 each. Lecturers were Gervais Chapuis (Lausanne, Switzerland), Marc de Boissieu (Grenoble, France), Michal Dusek
(Prague, Czech Republic), Joke Hadermann
(Antwerp, Belgium), Ron Lifshitz (Tel Aviv,
Israel), Olivier Pérez (Caen, France), Vaclav Petricek
(Prague, Czech Republic), Andreas Schönleber
(Bayreuth, Germany), Hiroyuki Takakura (Sapporo,
Japan) and Sander van Smaalen (Bayreuth,
Germany).
Lectures were organized
in slots of 90 minutes including a 5 minute break. Each lecture was
followed by a 30 minute break with coffee/tee and snacks. The first day
(Monday) was devoted to a refresher about diffraction and structure
determination (Schönleber), to a general introduction to aperiodic
crystals (van Smaalen), and to diffraction (Hadermann) and structural analysis by t-plots (Chapuis)
of modulated crystals. The second day (Tuesday) saw an introduction to quasicrystals (de Boissieu)
and structures of icosahedral quasicrystals (Takakura) as well as an introduction to the use of the
software JANA2006 (Petricek). Wednesday was again
devoted to modulated crystals with methods of structure solution (Dusek) and superspace
symmetry (van Smaalen). Lectures on Thursday were
about symmetry without superspace (Lifshitz), phasons (de Boissieu) and crystal chemistry of modulated structures
(Pérez). The morning of the last day (Friday) was used for lectures on
applications, including molecular crystals (Schönleber), phase transitions (Chapuis)
and electron microscopy of materials (Hadermann).
An important part of
the School was a practical course that allowed the participants to obtain a
working knowledge of structural analysis. Three afternoons have been
dedicated to these tutorials, which were offered in two parallel sessions
on "Structural analysis of modulated crystals with JANA2006" and
"Structures of quasicrystals",
respectively. The first tutorial was devoted to structural analysis of
modulated crystals with aid of the JANA2006 software. The second tutorial
was dedicated to the study of quasicrystals,
including approximants, analysis of the symmetry and crystal structures.
Both tutorials attracted about half of the participants.
The School started on
Sunday late afternoon with registration and a Welcome party in the evening,
on which drinks and light food were offered. On Wednesday evening the
participants presented and discussed their own research projects in a
poster session with food and beverages. On Thursday evening the Conference
dinner took place and on Friday afternoon, a visit commenced to the plant
of Bosch company in Bamberg, where spark plugs are manufactured, followed
by a guided tour through the cathedral and city of Bamberg, a UNESCO World
Heritage site.
Participants came from universities and
research institutes including departments of solid state physics, inorganic
chemistry, general chemistry, materials science and crystallography. This
list shows that interest in aperiodic crystals persists in all areas of
research on the solid state.
Marc de Boissieu, Andreas Schönleber and
Sander van Smaalen.
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Aperiodic crystals are
crystalline materials without translational symmetry. They encompass all
kinds of materials, including minerals, organic and inorganic compounds, the
elements, alloys, ferroelectrics, and proteins. The three types of
aperiodic order are incommensurately modulated structures, incommensurate composite crystals and quasicrystals.
The second school on
aperiodic crystals aims at introducing crystal structures of aperiodic
crystals. A series of lectures by experts in the field of aperiodic
crystals will present the basic features of the superspace
approach to structures and symmetry as well as to the use of these methods
in structural analysis, understanding physical properties and a
crystal-chemical interpretation of aperiodic crystals.
Separate tutorials will
be offered, where participants can practice the various steps of structural
analysis of incommensurately modulated structures or quasicrystals.
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