The free electron theory explains the properties like thermal conductivity, electrical conductivity and specific heat of most of the metals.
ELECTRON IN PERIODIC POTENTIAL 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. 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.Band theory of solids (Zone theory)
Postulates

Materials Science: Unit II(a): Electrical Properties of Materials : Tag: : - Electron in Periodic Potential
Materials Science
PH3251 2nd semester Mechanical Dept | 2021 Regulation | 2nd Semester Mechanical Dept 2021 Regulation
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