This document discusses various applications of magnetic materials including their use in electrical machines and permanent magnets. It describes low carbon steel as the most commonly used soft magnetic material due to its low cost and ability to minimize eddy current losses. Alnico alloys and hard ferrites are mentioned as important hard magnetic materials used in permanent magnets, with barium ferrite and strontium ferrites replacing older ferrites due to superior magnetic properties. Magnetic storage media is also summarized, noting it consists of magnetic oxide particles dispersed in a binder to allow individual particles to act as single domain magnets along their axis, with gamma ferric oxide being commonly used.

1. APPLICATIONS OF MAGNETIC
MATERIALS

2.  Soft magnetic materials – wide variety of electrical
machines
 Hard magnetic materials – Fabrication of permanent
magnets
 Magnetic Storage
Various Applications

3.  Minimises Eddy Current losses.
 Least expensive core material.
Low Carbon Steel(Fe-0.05% C)

4.  ‘Al,Ni,Co’,Fe(25-50%), Cu,Ti-minor constituents.
 High coercivity.
Alnico Alloys

5.  Also used in making permanent magnets.
 Most important hard ferrite is the barium ferrite(Ba
0.6 Fe2 O3 ).
 Nowadays replaced by strontium ferrites with
superior magnetic properties.
 Widely used in generators,loud speakers,telephone
ringers etc.
Hard Ferrites

6. MAGNETIC STORAGE

7.  Consists of magnetic oxide particles dispersed in a
binder.
 The oxide particles are needle like about 0.1 * 0.5 mm
size.
 Each particle is a single domain magnetized to
saturation along its major axis.
 Most commonly used particles are γ - Fe2 O3 with
length to width ratio of 5:1.
 Its coercivity is 20-28 kA/m.
Storage Medium

8. Flux reversal (or flux transition)
The recording process

9. Schematic arrangement
of a recording head of a
magnetic tape

10. Reading the data