Ferromagnetism isn’t the only type of magnetism, but it is the strongest kind, which means ferromagnetic materials come with their own set of advantages.
So just what is ferromagnetism, and which materials are ferromagnetic? Britannica explains ferromagnetism as the “physical phenomenon in which certain electrically uncharged materials strongly attract others.” Therefore, ferromagnetic materials are these elements that have a strong and spontaneous magnetism with or without an external magnetic field.
But that’s just the tip of what you should know about ferromagnetic materials. Keep reading to learn more about the fascinating materials.
Examples of Ferromagnetic Materials
Most materials that exhibit ferromagnetism are metals, such as metallic alloys and rare-earth magnets. The latter is considered the strongest magnet because they produce magnetic fields significantly stronger than any other.
The most widely known materials include Cobalt, Iron, Nickel. Other properties include Neodymium Magnet (a permanent magnet that is found in the earth’s crust), Terbium (invented in 1843 that is also found in the earth’s crust), and Dysprosium (a rare chemical element discovered in 1886 by Paul-Émile Lecoq de Boisbaudran). However, these are just a few of the various ferromagnetic materials.
It’s also important to note these materials are not a new discovery. They were first discovered over 2,000 years ago and were even utilized by the ancient Greeks who first called them “magnets” since they were able to attract similar properties.
Properties
Ferromagnetic materials have various unique properties. Here are some of the most significant:
- These materials can be permanently magnetic or gain attractive powers and can attract each other.
- They are strongly attracted to external magnetic fields.
- These elements can be permanently magnetic without an external magnetic force.
- At a high temperature, these substances change from ferromagnetic to paramagnetic (only magnetic when applied to an outside magnetic field).
Types of Ferromagnetic Materials
There are two ferromagnetic substance types. The first type is an unmagnetized ferromagnetic material. This substance will react to a magnetic force but will not be magnetic itself; it is only reactionary.
The second substance type is magnetized ferromagnetic material, which, when applied to a magnetic field, are coordinated, point in the same direction, and create powerful magnetic fields.
Advantageous and Disadvantages
Using substances that are ferromagnetic comes with various advantages and occasional disadvantages.
Advantages:
- The materials are cost-effective.
- Ferromagnetic substances are stable, especially compared to alternatives.
- Ferromagnets can operate at extremely high temperatures.
- These materials are highly resistant and permeable.
- They can be resistant to corrosion.
Disadvantages:
- The main disadvantage is ferromagnets’ weak magnetic fields.
- Some ferromagnetic types are fragile in high temperatures.
How the Materials Are Used Today
Despite being a widely unknown physical phenomenon, ferromagnetic materials play a large role in our day-to-day life. You can find these magnetic materials at work and in household items, such as hard drives, generators, telephones, and credit card magnetic strips. And, of course, nondestructive testing relies on ferromagnetism during Magnetic Particle Inspection (MPI).
To learn more about MPI and the way it uses ferromagnetic particles, visit this page for the latest NDT news.
