Imperfections In Crystal Lattice Structures

Imperfections are generally exist in lattice structurs of crystalline materials. In real life, there is no perfect crystalline materials that has zero imperfections inside their structure. In this article, we will explain the general imperfection situations in crystalline materials.

What Are The Imperfections In Crystalline Materials?

Imperfections in crystalline materials can be grouped into three; point defects, line defects and surface defects.

Point Defects; These defects are produced by situations from an individual atom, ion etc. in crystalline lattice structures.

• Vacancy: This is very simple to explain defect in crystalline lattice structures that is missing atom or molecule from lattice structure.
• Ion-pair Vacancy(Schottky Defect): This is the missing of a pair of ions from crystalline lattice structure.
• Interstitialcy: The crystal lattice distortion is caused by an excessive atom in the lattic structure.
• Displaced Ion(Frenkel Defect): In this defect, an ion is displaced into another place in crystal lattice structure, and the real place of this ion remains unfilled.

Line Defects; These defects are produced by situations from a line of atoms, ions etc. in crystalline lattice structures.

• Edge Dislocation: As you can observe from above, an extra plane of atoms is introduced into the crystalline lattice structure, and there is a distortion formed.
• Screw Dislocation: It is like a screw is wrapping around its axis, that a spiral formation is wrapped around an imperfection as shown above.

Surface Defetcs: This defects are responsible of shape of the related crystalline structure. These are generally observed as grain boundries in crystals. These grain boundries are generally utilized in obtaining certain material properties in varios materials.

The general expression of imperfections in crystalline structures are like that. Leave your comments and questions below about this topic!

Source of images: Fundamentals of modern manufacturing