**3. Types of modern permanent magnets and materials**

Modern permanent magnets are manufactured from different types of materials and systematic variations of compounds using different process. Based on composition variations in compounds, sub-lattice substitutions, crystallization of amorphous deposits and structure, permanent magnets are classified.

Generally, five different types of permanent magnets are known and produced for different purposes [14–16]. They are as follows:

i.Aluminium-nickel-cobalt (Alnico)

ii.Ferrite

These are M-type Sr- and Ba-hexaferrites

iii.Samarium-cobalt (SmCo)

Further in the Sm-Co family, again two types of permanent magnet such as SmCo5 and Sm2(Co,Fe,Cu,Zr)17 type are based on the variation of compositions and substitution of different elements.

iv.Neodymium-iron-boron (NdFeB) magnets

Similarly, NdFeB magnets are classified into sintered NdFeB (main phase is Nd2Fe14B), hot-deformed NdFeB magnets, bonded NdFeB produced using melt spun powder and bonded NdFeB magnets made from hydrogenation-disproportionationdesorption-recombination powder.

*Introductory Chapter: Modern Permanent Magnets – Basics and Applications DOI: http://dx.doi.org/10.5772/intechopen.113119*

v.SmFeN

SmFeN magnet, also known as Sm2Fe17N3, is a potential option for next generation of permanent magnetic material.
