A magnet is a material that produces an invisible field extending into the surrounding space, which exerts a force on other magnetic materials and moving electric charges. This capacity to create a persistent magnetic field is a rare property found in only a few elements on the periodic table. Permanent magnetism requires a highly specific atomic structure where the magnetic moments of electrons can align and remain fixed in that orientation. This article explores the specific elements used to manufacture the vast majority of commercial and industrial magnets, categorizing them by their function and the type of magnet they produce.
The Foundational Three Elements
Only three elements—Iron (Fe), Nickel (Ni), and Cobalt (Co)—exhibit ferromagnetism at standard room temperature, making them the fundamental building blocks for nearly all magnetic compounds. Ferromagnetism arises from the unique arrangement of electrons, specifically those in the outer d-orbitals, which possess an inherent spin that creates a tiny magnetic moment. In these elements, the magnetic moments of electrons do not cancel out, leading to a net atomic magnetic moment.
This intrinsic magnetism is amplified by exchange interaction, which forces the atomic moments to align parallel to each other within microscopic regions called magnetic domains. When an external magnetic field is applied, these domains align, and upon removal of the field, they remain largely aligned, resulting in a permanent magnet. Cobalt is the most thermally stable of the three, maintaining its magnetic properties up to its Curie temperature of approximately 1,121 degrees Celsius, while Iron’s Curie temperature is around 768 degrees Celsius.
Elements Used in High-Performance Magnets
The strongest permanent magnets utilize elements from the Lanthanide series, often called Rare Earth elements, which are prized for their unparalleled magnetic strength. Neodymium (Nd) forms the basis for the most powerful class of magnets, Neodymium-Iron-Boron (NdFeB), alloyed with Iron and the metalloid Boron (B). Neodymium’s unique electron structure provides extremely high magnetic anisotropy, meaning its atoms strongly prefer to be magnetized along a specific axis, yielding an exceptionally strong magnetic field in a small volume.
Another high-performance group is the Samarium-Cobalt (SmCo) magnets, which combine Samarium (Sm) with Cobalt. While slightly less powerful than NdFeB, Samarium-Cobalt magnets offer superior resistance to demagnetization at high temperatures. To enhance the temperature stability of Neodymium magnets, a secondary Rare Earth element, Dysprosium (Dy), is frequently added. Dysprosium increases the material’s coercivity—its ability to resist an external demagnetizing field—allowing NdFeB magnets to be used reliably in high-heat applications like electric vehicle motors and wind turbines.
Elements Used in Ceramic and Alloy Magnets
Beyond the Rare Earth magnets, other common magnet types rely on different elements to achieve specific magnetic properties, cost, and temperature ranges. Ceramic magnets, also known as ferrite magnets, are composed of Iron oxide combined with either Barium (Ba) or Strontium (Sr) to form a crystalline ceramic compound. Strontium ferrite is highly resistant to corrosion and offers high coercivity, meaning it retains its magnetism well, though its overall magnetic force is less than that of Rare Earth types.
Another significant group is the Alnico magnets, derived from the primary elements: Aluminum (Al), Nickel (Ni), and Cobalt (Co), which are alloyed with Iron. Alnico magnets are notable for their excellent temperature stability and are often used in applications such as sensors and guitar pickups. Small amounts of Copper (Cu) and sometimes Titanium (Ti) are also included in the Alnico formulation to enhance the alloy’s magnetic hardness, improving its resistance to demagnetization.