Five Things You Didn’t Know About Ferrite Magnets
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A Tale that Starts in Tokyo
The very first ferrite compounds were synthesized in 1930 by Yogoro Kato and Takeshi Takei of the Tokyo Institute of Technology. Five years after their initial discovery, the TDK Corporation was founded to manufacture the newly discovered material.
There are Two Types of Ferrite Magnets
It’s true that ferrite magnets are sometimes referred to as ceramic magnets. However, regardless of whether you call them ceramic magnets or ferrite magnets, there are still two different types of magnets within this category. The first type of ferrite magnet is barium ferrite, which was the first type of ferrite magnet to be discovered. The second type is strontium ferrite, which was developed after barium ferrite and today is the most common type of ferrite magnet due to having the best properties and performance.
Barium Ferrite Magnets Were Discovered on Accident
Speaking of barium ferrite, did you know this material was first discovered by mistake? In 1950, at the Phillips Natuurkundig Laboratorium, a lab assistant was preparing a sample of hexagonal lanthanum ferrite for research investigating its uses as a semiconductor material but made a mistake. To the research team’s surprise, the resulting material was actually magnetic. They confirmed the properties of the material using X-ray crystallography, and passed the newly discovered barium hexaferrite material on to the laboratory’s magnetic research group. Barium hexaferrite offered good performance at a low price, making it an immediate hit. A decade later, Phillips would go on to develop strontium hexaferrite, which came to dominate the market due to having better properties than barium hexaferrite.
Why Are They Called Ceramic Magnets?
Ferrite magnets are sometimes referred to as ceramic magnets due to similarities in their manufacturing process. If you’ve ever taken a pottery class, you will know that the final step in making a ceramic item is to put it in a kiln and fire it—that is, expose it to exceptionally high heat. When making a ferrite magnet, this process is referred to as “sintering.” In this step, the magnetic material is exposed to temperatures of approximately 2,000°F.
Ferrite Magnets Are Used in Many Applications
You can find ferrite magnets being used in many different applications, including telephones and loudspeakers, meters, generators, automotive sensors, and DC motors.