Zobrazeno 1 - 10
of 36
pro vyhledávání: '"Ted Janssen"'
Autor:
Ted Janssen
Publikováno v:
Symmetry, Vol 6, Iss 2, Pp 171-188 (2014)
An overview is given of the use of symmetry considerations for aperiodic crystals. Superspace groups were introduced in the seventies for the description of incommensurate modulated phases with one modulation vector. Later, these groups were also use
Externí odkaz:
https://doaj.org/article/aa3f6d32dcac428689b906470b7e4945
Over the past several decades, a This book deals with the characterisation of the structure, the structure determination and the study of the physical properties, especially dynamical and electronic properties of aperiodic crystals. The treatment is
Publikováno v:
Oxford Scholarship
This chapter discusses tilings as mathematical models for quasicrystals. In a first approximation quasicrystals may be described as being space filling with copies of two or more types of tiles. This description gives a connection with the mathematic
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::26410785ceaf86733d1170628f8a4cfd
https://doi.org/10.1093/oso/9780198824442.003.0003
https://doi.org/10.1093/oso/9780198824442.003.0003
This chapter discusses the X-ray and neutron diffraction methods used to study the atomic structures of aperiodic crystals, addressing indexing diffraction patterns, superspace, ab initio methods, the structure factor of incommensurate structures; an
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::3651fb9f41a05ade0cc3764fcca0f5d2
https://doi.org/10.1093/oso/9780198824442.003.0004
https://doi.org/10.1093/oso/9780198824442.003.0004
The law of rational indices to describe crystal faces was one of the most fundamental law of crystallography and is strongly linked to the three-dimensional periodicity of solids. This chapter describes how this fundamental law has to be revised and
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::7faff64664946c91a0165e48e7d1972f
https://doi.org/10.1093/oso/9780198824442.003.0007
https://doi.org/10.1093/oso/9780198824442.003.0007
Physical properties of aperiodic crystals present some theoretical challenges due to the lack of three-dimensional periodicity. For the description of the structure there is a periodic representation in higher-dimensional space. For physical properti
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::522c621021095aa81c7572d65eac5788
https://doi.org/10.1093/oso/9780198824442.003.0005
https://doi.org/10.1093/oso/9780198824442.003.0005
First a general description of the concept of crystalline structures is presented with some historical background information. The classical approach of periodic structures is presented along with the important topic of symmetry and its role characte
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::fca881edb796d19bb8394f04b4080459
https://doi.org/10.1093/oso/9780198824442.003.0001
https://doi.org/10.1093/oso/9780198824442.003.0001
Publikováno v:
Oxford Scholarship
This chapter first introduces the mathematical concept of aperiodic and quasiperiodic functions, which will form the theoretical basis of the superspace description of the new recently discovered forms of matter. They are divided in three groups, nam
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::0d00db626da1ab1165c46af10c1ff9b9
https://doi.org/10.1093/oso/9780198824442.003.0002
https://doi.org/10.1093/oso/9780198824442.003.0002
Autor:
Ted Janssen
Publikováno v:
Acta Crystallographica Section A Foundations and Advances. 72:296-297
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a26ac4a108bed3431ce10333b50bcf0f
https://doi.org/10.1107/s2053273316001935
https://doi.org/10.1107/s2053273316001935
Publikováno v:
Journal of Physics: Condensed Matter. 11:3209-3216
This paper explains the coexistence of the displacive and the order-disorder features of the ferroelectric phase transition in crystals. Both have been observed in experiments. The height of the potential barrier hindering the order parameter fluctua
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::46e9e11ab60c0ea6effb412a5b00b107
https://doi.org/10.1088/0953-8984/11/16/002
https://doi.org/10.1088/0953-8984/11/16/002