This book gives an overview of the preparation technique(sol-gel) and characterization of Al substituted in Nickel-Zinc nano-ferrites. Especially, this work focused on the area of characterization of structural properties like XRD, FTIR, SEM with EDS, magnetic properties (VSM), dielectric properties (AC conductivity), DC resistivity properties (using four probe method) and I-V characteristics. The content of this book help the researchers working in the area of nano technology for understanding an in-depth analysis of nano-ferrites of different types apart from Nickel-Zink due to the detailed procedural description involved in the characterization.