Solid State Physics Introduction

Updated: May 2, 2020


Crystalline nature of matter:

If the atoms or molecules in a solid are arranged in some regular periodic (array) then it is known as crystalline. When the atoms or molecules in a solid are arranged in an irregular fashion then it is known as amorphous.


A crystal is a solid composed of a periodic array of atoms i.e. a representative unit is repeated at regular intervals along with array and all directions.


The study of the geometric form and other physical properties of crystalline solids by using X-rays (by forming X-ray diffraction pattern), electron beams and neutron beams, etc., called crystallography.

Differences between crystalline and amorphous solids:

Space lattice:

Crystals made up of regular and periodic three-dimensional arrangements in space called the crystal structure. The periodic arrangement of atoms in a crystal is called the lattice. There is a group of several atoms or ions at each lattice point. This group is called a basis. So the crystal structure is formed when a basis of atoms is attached identically to each lattice point.