Simple Magnetism Definitions

• In order to understand the properties of materials that make magnetic materials there is some terminology which needs to be learned.
  
  Tesla: This is a unit of magnetic field. The higher the value, the higher the field.
  
  Coercive field: This is the magnetic field needed to demagnetize a magnetic material.
  
  Magnetizsation: This is the magnetic field within the material. The higher the value, the more magnetic a material is.
  
  

Iron

• Iron is the most commonly known ferromagnetic material. It has a coercive field of approximately 0.0002 T and a magnetization of 1700 A/m. It is commonly used in electromagnets and transformers, but is also a very important biological element. Iron is a fundamental constituent of hemoglobin, the red oxygen carrying pigment found in blood.
  
  

Cobalt

• Cobalt has a silvery-gray color and is commonly used in the computer hard drive industry as well as Lithium-ion batteries. Cobalt has a coercive field of approximately 0.002 T and a magnetization of 1400 A/m. Alloys of cobalt with the element samarium are very strong permanent magnets used in electrical motors.
  
  

Nickel

• Nickel is a well known magnetic element used in some American coins. It has a coercive field of approximately 0.0005 T, a magnetization of 490 A/m and hence is the least magnetic of the 3d transition ferromagnetic materials. Nickel alloys with iron to form a variety of technologically important materials, including Ni81Fe19, which is used in throughout the magnetic recording industry.