What is the difference between polycrystalline and amorphous

Examples of crystalline solids are diamond, benzoic acid, etc. Application of diamond includes in the making of beautiful jewelry, cutting of glass, etc. Amorphous refers to being shapeless. Amorphous solids have an irregular arrangement of the solid particles.

The intermolecular forces between them are not equal. Also, the distance between every two particles tends to vary. They do not possess a defined geometric shape. Amorphous solids are also known as supercooled liquids and they are isotropic in nature. Examples of amorphous solids include glass, naphthalene, etc. Applications of glass are as follows. It is widely used for the construction of buildings. It is also used in the packaging of cosmetics such as cosmetics boxes and the packing of food items such as in making food jars.

For understanding the difference between amorphous solids and crystalline solids better, let us take a look at the table given below. In an isotropic polycrystalline solid, there is no relationship between neighbouring grains. Therefore, on a large enough length scale, there is no periodicity across a polycrystalline sample. Amorphous materials, like window glass, have no long-range order at all, so they have no translational symmetry.

The structure of an amorphous solid and indeed a liquid is not truly random - the distances between atoms in the structure are well defined and similar to those in the crystal. This is why liquids and crystals have similar densities - both have short-range order that fixes the distances between atoms, but only crystals have long-range order. The range of crystalline order distinguishes single crystals, polycrystals and amorphous solids.

The figure shows how the periodicity of the atomic structure of each type of material compares. Many characteristic properties of materials, such as mechanical, optical, magnetic and electronic behaviour, can be attributed to the difference in structure between these three classes of solid. Upvote 2. The questions I like to address in this area are:. I am also interested in developing theories and computational methods for obtaining the effective elastic and thermal properties of composite materials under static and quasi-static loading.

To this end, I am interested in developing continuum-to-continuum theories or homogenization methods that are able to connect two continuum scales. Kranthi K. Previous Next Introduction The fundamental difference between single crystal, polycrystalline and amorphous solids is the length scale over which the atoms are related to one another by translational symmetry 'periodicity' or 'long-range order'.

An ideal single crystal has an atomic structure that repeats periodically across its whole volume. Even at infinite length scales, each atom is related to every other equivalent atom in the structure by translational symmetry. A polycrystalline solid or polycrystal is comprised of many individual grains or crystallites.