**1. Introduction**

Permanent magnets are highly magnetized functional hard materials, which do not lose magnetism over time due to the generation of magnetic field by the internal structure of the material itself [1–3]. These modern permanent magnets are made from a "cocktail" of minerals which can include iron, neodymium, samarium, cobalt and nickle. Normally, the functionality of the permanent magnets depends on the intrinsic properties of the base compound. It is commonly known that permanent magnets are source of magnetic field. The composition, extrinsic properties such as microstructure and processing method of materials are define the magnetic properties of the permanent magnets [4–6].
