*Walter Steurer and Julia Dshemuchadse*

- Published in print:
- 2016
- Published Online:
- September 2016
- ISBN:
- 9780198714552
- eISBN:
- 9780191782848
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198714552.003.0008
- Subject:
- Physics, Crystallography

The focus of this chapter is complex intermetallics. The term “complex” is commonly used intuitively for big structures with distinct structural subunits and related different length scales. Thus, ...
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The focus of this chapter is complex intermetallics. The term “complex” is commonly used intuitively for big structures with distinct structural subunits and related different length scales. Thus, more qualitative than quantitative criteria are usually applied when classifying a structure to be complex. However, for a statistical analysis of a big database, one needs well-defined parameters for a classification of structures into complex and non-complex ones, which will be discussed here. The purpose of such a classification is the identification of intermetallic compounds that have structures with different structural length scales, that on the scale of atoms and that on the scale of endohedral clusters or other structural subunits. These different length scales can be the origin of interesting physical properties, which may lead to useful applications.Less

The focus of this chapter is complex intermetallics. The term “complex” is commonly used intuitively for big structures with distinct structural subunits and related different length scales. Thus, more qualitative than quantitative criteria are usually applied when classifying a structure to be complex. However, for a statistical analysis of a big database, one needs well-defined parameters for a classification of structures into complex and non-complex ones, which will be discussed here. The purpose of such a classification is the identification of intermetallic compounds that have structures with different structural length scales, that on the scale of atoms and that on the scale of endohedral clusters or other structural subunits. These different length scales can be the origin of interesting physical properties, which may lead to useful applications.

*Walter Steurer and Julia Dshemuchadse*

- Published in print:
- 2016
- Published Online:
- September 2016
- ISBN:
- 9780198714552
- eISBN:
- 9780191782848
- Item type:
- book

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198714552.001.0001
- Subject:
- Physics, Crystallography

The focus of this book is clearly on the statistics, topology, and geometry of crystal structures and crystal structure types. This allows one to uncover important structural relationships and to ...
More

The focus of this book is clearly on the statistics, topology, and geometry of crystal structures and crystal structure types. This allows one to uncover important structural relationships and to illustrate the relative simplicity of most of the general structural building principles. It also allows one to show that a large variety of actual structures can be related to a rather small number of aristotypes. It is important that this book is readable and beneficial in the one way or another for everyone interested in intermetallic phases, from graduate students to experts in solid-state chemistry/physics/materials science. For that purpose it avoids using an enigmatic abstract terminology for the classification of structures. The focus on the statistical analysis of structures and structure types should be seen as an attempt to draw the background of the big picture of intermetallics, and to point to the white spots in it, which could be worthwhile exploring. This book was not planned as a textbook; rather, it should be a reference and guide through the incredibly rich world of intermetallic phases. In the first part of the book the basic concepts and tools are presented for the description of symmetry and structures of metallic elements and intermetallic phases, periodic and quasiperiodic ones, while in the second part the focus is on the discussion of their actual structures and properties.Less

The focus of this book is clearly on the statistics, topology, and geometry of crystal structures and crystal structure types. This allows one to uncover important structural relationships and to illustrate the relative simplicity of most of the general structural building principles. It also allows one to show that a large variety of actual structures can be related to a rather small number of aristotypes. It is important that this book is readable and beneficial in the one way or another for everyone interested in intermetallic phases, from graduate students to experts in solid-state chemistry/physics/materials science. For that purpose it avoids using an enigmatic abstract terminology for the classification of structures. The focus on the statistical analysis of structures and structure types should be seen as an attempt to draw the background of the big picture of intermetallics, and to point to the white spots in it, which could be worthwhile exploring. This book was not planned as a textbook; rather, it should be a reference and guide through the incredibly rich world of intermetallic phases. In the first part of the book the basic concepts and tools are presented for the description of symmetry and structures of metallic elements and intermetallic phases, periodic and quasiperiodic ones, while in the second part the focus is on the discussion of their actual structures and properties.

*Walter Steurer and Julia Dshemuchadse*

- Published in print:
- 2016
- Published Online:
- September 2016
- ISBN:
- 9780198714552
- eISBN:
- 9780191782848
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198714552.003.0003
- Subject:
- Physics, Crystallography

Crystal structures, be they periodic or aperiodic, can be described in many different ways: as lattices, tilings, or coverings decorated by atoms or clusters on one hand, or as packings of structural ...
More

Crystal structures, be they periodic or aperiodic, can be described in many different ways: as lattices, tilings, or coverings decorated by atoms or clusters on one hand, or as packings of structural subunits (AETs, clusters, modules, etc.) on the other hand. In this chapter the decomposition of crystal structures into AETs and clusters is discussed, as well as tilings and coverings. This ranges from the 1D quasiperiodic Fibonacci sequence to examples of 2D and 3D periodic as well as quasiperiodic tilings. The standard unit cell description of periodic crystal structures corresponds to a specific tiling approach with just a single prototile with the shape of a parallelepiped, i.e., the crystallographic unit cell. The detailed discussion of periodic and quasiperiodic tilings and packings can be quite helpful in understanding structural building principles of complex intermetallics, periodic as well as quasiperiodic ones.Less

Crystal structures, be they periodic or aperiodic, can be described in many different ways: as lattices, tilings, or coverings decorated by atoms or clusters on one hand, or as packings of structural subunits (AETs, clusters, modules, etc.) on the other hand. In this chapter the decomposition of crystal structures into AETs and clusters is discussed, as well as tilings and coverings. This ranges from the 1D quasiperiodic Fibonacci sequence to examples of 2D and 3D periodic as well as quasiperiodic tilings. The standard unit cell description of periodic crystal structures corresponds to a specific tiling approach with just a single prototile with the shape of a parallelepiped, i.e., the crystallographic unit cell. The detailed discussion of periodic and quasiperiodic tilings and packings can be quite helpful in understanding structural building principles of complex intermetallics, periodic as well as quasiperiodic ones.