Materials Science: Unit II(a): Electrical Properties of Materials

Electron in Periodic Potential

The free electron theory explains the properties like thermal conductivity, electrical conductivity and specific heat of most of the metals.

ELECTRON IN PERIODIC POTENTIAL

Band theory of solids (Zone theory)

The free electron theory explains the properties like thermal conductivity, electrical conductivity and specific heat of most of the metals.

But, it fails to explain why some solids are conductors, some are insulators and others are semiconductors.

A solution to this problem was given by band theory of solids and is called zone theory.

According to free electron theory, the potential energy of the electron inside the crystal through which an electron moves is supposed to be constant (zero). So it is completely free to move about in the crystal, restrained only by the surface of the crystal.

Postulates

1. According to band theory, potential energy of electron within the crystal is periodic due to periodicity of the crystal i.e., free electrons move inside periodic lattice field.

2. The potential energy of the solid varies periodically with the periodicity of space lattice 'a' which is nothing but interatomic spacing.

Inside a real crystal, the electrons (-) move through periodic arrangement of positively charged holes (+) as shown in the fig.(2.13a)

Fig. (2.13b) shows one dimensional periodic potential distribution for a crystal. It is assumed that the potential energy of the electron at the positive ion site is zero and is maximum when it is half way between the adjacent nuclei.


Materials Science: Unit II(a): Electrical Properties of Materials : Tag: : - Electron in Periodic Potential


Materials Science: Unit II(a): Electrical Properties of Materials



Under Subject


Materials Science

PH3251 2nd semester Mechanical Dept | 2021 Regulation | 2nd Semester Mechanical Dept 2021 Regulation



Related Subjects


Professional English II

HS3251 2nd Semester 2021 Regulation | 2nd Semester Common to all Dept 2021 Regulation


Statistics and Numerical Methods

MA3251 2nd Semester 2021 Regulation M2 Engineering Mathematics 2 | 2nd Semester Common to all Dept 2021 Regulation


Engineering Graphics

GE3251 eg 2nd semester | 2021 Regulation | 2nd Semester Common to all Dept 2021 Regulation


Physics for Electrical Engineering

PH3202 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation


Basic Civil and Mechanical Engineering

BE3255 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation


Electric Circuit Analysis

EE3251 2nd Semester 2021 Regulation | 2nd Semester EEE Dept 2021 Regulation


Physics for Electronics Engineering

PH3254 - Physics II - 2nd Semester - ECE Department - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation


Electrical and Instrumentation Engineering

BE3254 - 2nd Semester - ECE Dept - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation


Circuit Analysis

EC3251 - 2nd Semester - ECE Dept - 2021 Regulation | 2nd Semester ECE Dept 2021 Regulation


Materials Science

PH3251 2nd semester Mechanical Dept | 2021 Regulation | 2nd Semester Mechanical Dept 2021 Regulation


Basic Electrical and Electronics Engineering

BE3251 2nd semester Mechanical Dept | 2021 Regulation | 2nd Semester Mechanical Dept 2021 Regulation


Physics for Civil Engineering

PH3201 2021 Regulation | 2nd Semester Civil Dept 2021 Regulation


Basic Electrical, Electronics and Instrumentation Engineering

BE3252 2021 Regulation | 2nd Semester Civil Dept 2021 Regulation


Physics for Information Science

PH3256 2nd Semester CSE Dept | 2021 Regulation | 2nd Semester CSE Dept 2021 Regulation


Basic Electrical and Electronics Engineering

BE3251 2nd Semester CSE Dept 2021 | Regulation | 2nd Semester CSE Dept 2021 Regulation


Programming in C

CS3251 2nd Semester CSE Dept 2021 | Regulation | 2nd Semester CSE Dept 2021 Regulation