Introduction
Magnets play an important role in our day-to-day lives, but did you know that not all magnets are created equal? Some magnets are "hard" and maintain their magnetic field for a long time, while others are "soft" and tend to lose their magnetic properties quickly.
In this article, we will take a closer look at soft magnets and provide an example of one such magnet.
What are soft magnets?
Soft magnets, also known as non-permanent magnets or temporary magnets, are materials that exhibit magnetic properties under certain conditions but lose their magnetism quickly once those conditions are removed. Soft magnets are commonly used in applications where the magnetic field is only needed temporarily or where the magnetic field needs to be easily reversed or shifted.
Soft magnets are made of materials that have low coercivity and low remanence. Coercivity is a material''s resistance to becoming magnetized, while remanence is a material''s ability to retain its magnetic field even after the magnetizing force is removed.
Soft magnetic materials
There are several soft magnetic materials that are commonly used in various applications. These materials include:
1. Iron
Iron is one of the most common materials used for soft magnets. Iron has low coercivity and low remanence, making it an ideal choice for temporary magnetic structures.
2. Silicon iron
Silicon iron is another commonly used soft magnetic material. It is an alloy of iron and silicon, and its unique properties allow it to be used in electrical transformers and motor cores.
3. Nickel-iron alloys
Nickel-iron alloys, also known as permalloys, are another type of soft magnetic material. They are used in magnetic shielding applications and in the production of electrical components.
Example of a soft magnet
One common example of a soft magnet is the magnetic stripe found on the back of credit cards. The magnetic stripe is made up of a thin layer of ferromagnetic material that can be magnetized when exposed to a magnetic field.
When you swipe your credit card at a point of sale terminal, the magnetic stripe comes into contact with a magnetic head, which reads the information stored on the stripe and processes the transaction.
The magnetic stripe on a credit card is a perfect example of a soft magnet because it only needs to maintain its magnetic properties temporarily.
Conclusion
Soft magnets are an important aspect of many everyday applications. They are used in situations where the magnetic field only needs to be temporary or easily reversible.
Materials like iron, silicon iron, and nickel-iron alloys are commonly used for these applications. And if you''ve ever used a credit card with a magnetic stripe, you''ve interacted with a soft magnet firsthand!
Understanding the properties and uses of soft magnets can help us better appreciate the many ways in which materials science impacts our lives.
