Magnets are fascinating objects that have been captivating humans for centuries. They are found in various forms and strengths, from the simple fridge magnets to the powerful ones used in advanced technologies. In this article, we will explore the top 10 strongest magnets found on Earth, including natural and man-made examples. We will delve into their properties, uses, and unique characteristics.
1. Magnetite
Magnetite, also known as lodestone, is a naturally occurring iron oxide mineral (Fe3O4) with a Mohs hardness scale of 5.5 to 6. It is one of the most common and strongest naturally occurring magnets on Earth. Its magnetic properties are due to the presence of iron and its crystal structure. Magnetite has been used by ancient civilizations for navigation and compass-making. Today, it is primarily used in the production of iron and steel, as well as in magnetic applications such as speaker magnets and magnetic recording tapes.
Properties
* Chemical formula: Fe3O4
* Crystal structure: Hexagonal
* Mohs hardness: 5.5-6
* Magnetic strength: 5-6 kOe (kiloOersted)
2. Neodymium magnet
Neodymium magnets, also known as neodymium iron boron (NdFeB) magnets, are man-made magnets made from an alloy of neodymium, iron, and boron. They are the strongest permanent magnets commercially available, with a magnetic strength up to 18,000 kOe. They were developed in the 1980s and have since replaced other types of magnets in various applications due to their high strength and low cost.
Properties
* Chemical formula: NdFeB
* Crystal structure: Hexagonal
* Mohs hardness: 5-6
* Magnetic strength: Up to 18,000 kOe
3. Samarium Cobalt Magnet
Samarium cobalt (SmCo) magnets are another type of man-made rare earth magnet, made from an alloy of samarium and cobalt. They have a high resistance to demagnetization and can retain their magnetic properties up to high temperatures, making them suitable for high-temperature applications. They are commonly used in motors, generators, and sensors.
Properties
* Chemical formula: SmCo
* Crystal structure: Hexagonal
* Mohs hardness: 6-7
* Magnetic strength: Up to 15,000 kOe
4. Alnico Magnet
Alnico magnets are man-made magnets made from an alloy of aluminum, nickel, and cobalt, with small amounts of other elements like iron and titanium. They have a high magnetic strength, good corrosion resistance, and high temperature stability, making them suitable for applications in harsh environments. Alnico magnets are commonly used in motors, generators, and audio speakers.
Properties
* Chemical formula: AlNiCo
* Crystal structure: Cubic
* Mohs hardness: 6-7
* Magnetic strength: Up to 10,000 kOe
5. Ferrite Magnet
Ferrite magnets, also known as ceramic magnets, are man-made magnets made from a sintered ceramic material of iron oxide and one or more of the following metals: barium, strontium, or lead. They have a high resistance to demagnetization, good temperature stability, and low cost, making them suitable for applications in motors, generators, and transformers.
Properties
* Chemical formula: Fe