When electron and the crystalline materials interact to each other then it produce rings or spots which is characterize as the sample. The wavelength of the electron can be represented by
Wavelength of he electron can be controlled by controlling the speed of the electron.
Crystalline lattice is the array of atoms, which is called unit cells, which is repeated over and over again. Since the vertices of the unit cell are atoms, the size of the unit cell is related to the inter-atomic spacing, or lattice constant which is represented as a.