Line imperfections are called dislocations. There are two primary types of dislocations. These are: Edge dislocation, and Screw dislocation. Edge Dislocations To understand an edge dislocation, consider a perfect crystal shown in Figure 1(a). Atoms (not shown in diagram) are located on each cross-point in it. A perfect crystal is Read more…
A perfect (ideal) crystal is a perfectly ordered arrangement of atoms at the points of infinite space lattice. Any departure from this idealized arrangement makes the crystal imperfect. A perfect single crystal is rarely available. Crystalline materials have real crystals. They are of finite dimensions. They have broken bonds at Read more…
Structures of solids can be determined by various techniques. Out of these techniques, X-rays and microscopic studies have helped immensely in studying crystallography of metals. Therefore these two techniques are very popular. Hence X-rays will be discussed in this article and microscopy is discussed in another one. X-RAYS X-rays have Read more…
Miller is the name of a material scientist. Indices is plural of index. Miller indices are the styles to designate the planes and directions in the unit cells and crystals. Such designations become essential for investigations of various properties in different elements. In the most general way, Miller indices are Read more…
Solids, on the basis of their structures, may be classified as: Inorganic solids: (a) Metallic solids (b) Ionic solids (c) Covalent solids Organic (or molecular) solids Complex structure solids Examples of such solids are as under: Metallic solids: Na, Cu, Zn; compounds such as borides, hydrides, nitrides, carbides etc. formed Read more…
1. Unit cell and Crystal A unit cell is defined as the basic structural part in the composition of materials. It is analogous to a brick used in the building construction. When many unit cells repeat in a three-dimensional space, a crystal is obtained. The structure of a crystal is Read more…
The study of geometry and structure of solids is a science known as crystallography. X-rays and microscopes have substantially contributed to this area. The atoms and molecules are held together by chemical bonds in the solids. The orientation, periodicity, and symmetries of atoms and molecules vary widely. The arrangement of Read more…