This book is based on some fundamental research about the structural, electromagnetic and dielectric properties of magnetic materials. Sample preparation methodology, experimental techniques, relevant theories regarding the descriptions of structural, magnetic, electrical and dilectric properties of ferrimagnetic materials have been discussed in the light of earlier literature and from the present work. For these reasons, it is believed that this book will give fundamental ideas about the understanding of various properties of soft and hard magnetic materials. Students and researchers working on the area of ferrites, magnetic and dielectric materials might be able to get some basic ideas and references from this research and literature based book. Any comments and suggessions regarding the improvment of this book will be greatly appreciated.