This is an introductory book on electronic materials intended for students of Electronics, Computer Science, Electrical Engineering and Material Science. The importance of semiconductors, ferro and ferri magnetic, dielectric and ferroelectric materials in modern electronic engineering is reflected by the large number of rapidly growing research and development establishments in these fields. All electrical and electronic devices employ the above materials in one form or other. Therefore, the basic understanding of the natural behaviour of the material is a prerequisite for students in Engineering and Technology. With the developments in electronic and electrical industry, there is a greater responsibility on the shoulders of the engineers and physicists to work on basics more elaborately and intuitively. The fabrication of devices requires a thorough understanding of physical concepts involved in the fundamental properties of the materials.