1. Applications 14

2. 14.1 Introduction

3. 14.2 Electrical Steels (Soft Magnetic Materials)
Electrical steel is used to multiply the magnetic flux in the cores of electromagnetic coils – transformers, electro-motors, generators, electromagnets.
- Highest possible permeability, and easily magnetize and demagnetize it.
Core Losses
: The energy that is dissipated in the form of heat within the core of electromagnetic devices when the core is subjected to an alternating magnetic field
Eddy current loss
Hysteresis loss

4. In order to decrease the eddy current,
The core can be made of an insulator – use ferrites
The core can be made from pressed iron powder whereby each powder is covered by an insulating coating.- decrease in s resulted in large decrease in m
Made out of thin sheets which are electrically insulated from each other

5. 14.2.2 Grain Orientation Magnetic Anisotropy Easy Direction
The magnetic properties of Crystalline ferromagnetic materials depend on the crystallographic direction in which an external field is applied
Magnetization curves of single crystals
If the external field is applied in the <100> direction, saturation is achieved with the smallest possible field strength
Easy Direction

6. 14.2.3 Composition of Core Materials
Low carbon steel
: The least expensive core material -> relatively small permeability, higher core losses than grain-oriented silicon iron
Iron-silicon alloys
: higher permeability and a lower conductivity than low carbon steel, heat treatments of these alloys can be performed at much higher temperatures without interference from phase changes during cooling
Permalloy, Supermalloy, Mumetal
: The highest permeability (multicomponent nickel based alloys)
Amorphous Ferromagnets
- a considerably higher permeability and a lower coercivity
- electrical resistivity is generally larger

7. 14.3 Permanent Magnets (Hard Magnetic Materials)
: Devices that retain their magnetic field indefinitely.
Hard magnetic materials
Demagnetization curve
Maximum energy product

9. Demagnetizing Curve

10. 14.4 Magnetic Recording and Magnetic Memories