Magnetic Material

Essen Magnetics offers a range of magnetic materials for permanent magnets.

NdFeB Magnets

NdFeB magnets also known as neodymium magnets or rare-earth magnets, are the strongest type of permanent magnets available commercially. Composed mainly of neodymium (Nd), iron (Fe), and boron (B), they belong to the family of rare-earth magnets and exhibit exceptional magnetic strength compared to other materials.

Key Features of NdFeB Magnets

High Magnetic Strength

NdFeB magnets offer the highest magnetic strength of any permanent magnet, making them ideal for applications where a strong magnetic field is critical.

Compact Size

Due to their powerful magnetic properties, NdFeB magnets can be small and still produce significant magnetic force, which is advantageous in applications requiring miniaturization.

Good Temperature Performance

Standard grades of NdFeB magnets operate well at moderate temperatures, but they can lose strength when exposed to high temperatures. However, high-temperature grades are available to maintain performance in more extreme environments.

Corrosion-Prone

NdFeB magnets are susceptible to corrosion, so they are often coated with protective materials like nickel, zinc, or epoxy to improve their durability and resistance to environmental conditions.

Applications

NdFeB magnets are used across a wide range of industries due to their strength and versatility, including:

Motors and Generators

From small electric motors in consumer electronics to large industrial motors, these magnets provide efficient, high-power output.

Medical Devices

NdFeB magnets are critical in devices like MRI machines and other precision instruments.

Consumer Electronics

Smartphones, headphones, and other gadgets benefit from their compact, powerful properties.

Green Energy

Wind turbines and electric vehicles use NdFeB magnets to optimize performance and efficiency.

Despite their higher cost compared to other magnets, the performance benefits of NdFeB magnets make them indispensable in many advanced technological applications.

MAGNETIC PROPERTIES

SmCo Magnets

SmCo magnets or samarium cobalt magnets, are a type of rare-earth magnet made from an alloy of samarium (Sm) and cobalt (Co). These magnets are known for their exceptional magnetic strength, excellent temperature stability, and resistance to corrosion. They are the second strongest type of permanent magnets, following neodymium (NdFeB) magnets, but offer advantages in certain high-temperature and harsh environmental applications.

Key Features of SmCo Magnets

High Magnetic Strength

SmCo magnets have strong magnetic properties, though they are slightly weaker than NdFeB magnets. However, they outperform most other magnets like ferrite and Alnico in terms of magnetic strength.

Exceptional Temperature Stability

SmCo magnets can operate at higher temperatures (up to 350°C or 662°F) without losing their magnetic properties, making them ideal for applications that involve extreme heat.

Corrosion and Oxidation Resistance

Unlike NdFeB magnets, SmCo magnets are highly resistant to corrosion and do not require surface coatings to protect them in harsh or humid environments.

Brittleness

SmCo magnets are very hard and brittle, making them prone to cracking or breaking if handled roughly. This characteristic requires careful handling and, in some cases, protective housing in mechanical applications.

High Coercivity

They have strong resistance to demagnetization, even in high-temperature environments or under external magnetic fields.

Applications

SmCo magnets are often used in specialized industries and applications that demand high magnetic strength, stability at extreme temperatures, and resistance to corrosion:

Aerospace and Military

SmCo magnets are often used in aircraft, spacecraft, and defense applications due to their high temperature and corrosion resistance.

Motors and Generators

SmCo magnets are employed in high-performance motors and generators, especially where the machinery is exposed to high temperatures.

Medical Devices

In medical devices such as MRI machines and surgical instruments, SmCo magnets provide precision and stability.

Automotive and Sensors

These magnets are used in automotive sensors and other critical components that operate in high-heat environments.

Marine Applications

Due to their corrosion resistance, SmCo magnets are suitable for marine environments where saltwater exposure can damage other types of magnets.

While SmCo magnets are more expensive than ferrite and Alnico magnets and slightly costlier than NdFeB magnets, their superior thermal stability and resistance to corrosion make them the preferred choice for demanding and high-performance applications.

MAGNETIC PROPERTIES

Alnico Magnets

Alnico magnets are a type of permanent magnet made primarily from aluminum (Al), nickel (Ni), and cobalt (Co), along with small amounts of other elements such as copper and iron. They were among the first widely used permanent magnets before the development of rare-earth magnets like NdFeB. While not as strong as rare-earth magnets, Alnico magnets are still highly valued for their unique properties.

Key Features of Alnico Magnets

Temperature Stabilit

Alnico magnets have excellent temperature stability, retaining their magnetic properties even at high temperatures (up to 500°C or 932°F). This makes them ideal for use in high-heat environments where other magnets may lose strength.

Corrosion Resistance

Alnico magnets are naturally resistant to corrosion, so they do not typically require protective coatings like NdFeB magnets.

High Remanence and Low Coercivit

Alnico magnets have high magnetic remanence (the ability to retain magnetism) but low coercivity, meaning they can be demagnetized relatively easily. This characteristic is useful in some applications but can also be a limitation where strong resistance to demagnetization is required.

Versatility in Shapes

Alnico magnets can be produced in a wide variety of shapes and sizes, including complex geometries, making them versatile for various applications.

Applications

Due to their stability at high temperatures and good resistance to corrosion, Alnico magnets are often used in applications where these specific properties are required:

Sensors and Instruments

Alnico magnets are commonly used in measuring devices, sensors, and compasses due to their stability and durability.

Motors and Generators

These magnets are used in specialized motors and generators, particularly in applications involving high temperatures.

Loudspeakers

The vintage sound quality produced by Alnico magnets has made them a favorite in high-end loudspeakers and guitar amplifiers.

Holding Devices

In magnetic clamps, holders, and jigs, Alnico magnets provide reliable, durable magnetic strength. Although Alnico magnets are not as strong as modern rare-earth magnets, their ability to perform in extreme temperatures and environments continues to make them a valuable option for many industrial and technical uses.

MAGNETIC PROPERTIES

Hard ferrite (Ceramic) Magnets

Hard ferrite (Ceramic) magnets also known as ceramic magnets, are permanent magnets made primarily from iron oxide (Fe₂O₃) mixed with either barium carbonate (BaCO₃) or strontium carbonate (SrCO₃). These magnets are widely used due to their low cost, resistance to corrosion, and good magnetic strength.

Key Features of Hard Ferrite (Ceramic) Magnets

Low Cost

Hard ferrite magnets are inexpensive to produce, making them a cost-effective choice for many applications compared to rare-earth magnets like NdFeB or Alnico.

Good Corrosion Resistance

Ceramic magnets are naturally resistant to corrosion and do not require additional coatings or treatments to protect against environmental conditions.

Moderate Magnetic Strength

While not as strong as NdFeB or SmCo magnets, hard ferrite magnets still provide adequate magnetic force for many applications, especially where cost-efficiency and durability are priorities.

Brittle and Hard

Ferrite magnets are hard and brittle, making them more prone to cracking or chipping if not handled carefully. However, their hardness allows for excellent resistance to demagnetization.

Temperature Stability

These magnets can operate in temperatures up to 250°C (482°F) without significant loss of magnetism, although their performance declines at very high temperatures.

Applications

Due to their affordability and practical properties, hard ferrite magnets are widely used in various industries, particularly where strong magnetic fields aren’t a critical requirement:

Motors

Ferrite magnets are commonly used in electric motors for household appliances, automotive applications, and industrial machinery.

Speakers

They are used in loudspeakers and audio equipment due to their ability to produce a stable magnetic field at a low cost.

Magnetic Separators

Ferrite magnets are often employed in magnetic separation systems, used to remove ferrous contaminants in industries like mining, recycling, and food production.

Magnetic Holding

Commonly found in refrigerator magnets, magnetic catches, and other holding devices.

Magnet Assemblies

Ferrite magnets are used in a variety of assemblies for everyday products, like magnetic tool holders and magnetic clasps in accessories.

Hard ferrite magnets are popular due to their balance of affordability, corrosion resistance, and adequate magnetic strength, making them a reliable choice for mass-market and industrial applications where high-performance magnets are not essential.

MAGNETIC PROPERTIES

FeCrCo Magnets

FeCrCo magnets are a type of magnet alloy primarily composed of iron (Fe), chromium (Cr), and cobalt (Co). They are known for their good machinability, moderate magnetic properties, and resistance to corrosion, making them suitable for specialized applications where shaping and forming magnets into complex designs is required. While not as strong as other permanent magnets like NdFeB, SmCo, or even Alnico, FeCrCo magnets have unique advantages that make them useful in certain industries.

Key Features of FeCrCo Magnets

Good Machinability

One of the standout features of FeCrCo magnets is their excellent machinability. Unlike other magnets that are brittle, FeCrCo magnets can be easily machined, cut, drilled, and shaped into intricate geometries, making them ideal for custom applications.

Moderate Magnetic Strength

FeCrCo magnets have lower magnetic strength compared to rare-earth magnets and Alnico, but they still offer a stable and reliable magnetic field for moderate magnetic applications.

Temperature Stability

These magnets can operate in temperatures up to 400°C (752°F) while maintaining their magnetic properties, offering good performance in environments where temperature resistance is critical.

Corrosion Resistance

FeCrCo magnets exhibit good resistance to corrosion, making them suitable for use in environments where other magnets might degrade or oxidize.

Flexible Manufacturing

Due to their machinability and ability to be hot-rolled, drawn, and formed, FeCrCo magnets can be produced in various shapes and forms, such as thin wires, sheets, and more.

Applications

Because of their unique combination of machinability, moderate magnetism, and corrosion resistance, FeCrCo magnets are used in various specialized applications, including:

Precision Instruments

FeCrCo magnets are often used in instruments and devices where custom-shaped magnets are required, such as in measuring equipment, sensors, and magnetic relays.

Magnetic Recording

They can be found in certain magnetic recording devices, where a stable magnetic field is needed to interact with media.

Security Systems

FeCrCo magnets are used in security and locking systems, where customized magnets are essential for precision.

Aerospace and Military

These magnets are also utilized in aerospace and military applications that require good corrosion resistance and the ability to perform in high-temperature environments.

Although FeCrCo magnets do not offer the same level of magnetic power as stronger rare-earth magnets, their ability to be shaped into complex forms and their stable performance in varying environmental conditions make them a valuable choice for industries that require flexibility in design and durability.

Typical Magnetic Properties of FeCrCo Magnets

NANO Cores

A nanocrystalline core is a magnetic core made from nanocrystalline soft magnetic materials, which are formed by rapid solidification of metallic alloys followed by controlled heat treatment. These materials consist of ultra-fine grains (10–20 nm), which significantly enhance their magnetic properties compared to traditional materials like ferrites, silicon steel, and amorphous alloys.

Nanocrystalline cores offer high permeability, low core loss, high saturation flux density, and excellent temperature stability, making them ideal for high-frequency and high-efficiency power applications.

Composition of Nanocrystalline Cores

Nanocrystalline cores are primarily made of iron (Fe), silicon (Si), boron (B), niobium (Nb), and copper (Cu), following an Fe-based composition such as Fe-Si-B-Nb-Cu.

Applications of Nanocrystalline Cores

Due to their superior magnetic properties, nanocrystalline cores are widely used in various high-performance electrical and electronic systems:

Electromagnetic Compatibility (EMC) & EMI Suppression

· Common Mode Chokes (CMC): Used in power lines, data lines, and automotive electronics to reduce electromagnetic interference (EMI).

· Differential Mode Inductors: Improve power quality and filter unwanted signals.

High-Frequency Power Transformers

· Switched-Mode Power Supplies (SMPS): Used in data centers, telecom power supplies, and industrial electronics.

· DC-DC Converters: Improve power efficiency in electric vehicles (EVs) and renewable energy systems.

· Resonant Transformers: Used in induction heating and wireless power transmission.

Renewable Energy & Power Electronics

· Photovoltaic (PV) Inverters: Improve efficiency and reduce losses in solar power conversion.

· Wind Power Converters: Used in wind energy systems for stable power conversion.

· Uninterruptible Power Supplies (UPS): Provide stable and efficient energy storage and conversion.

Automotive Applications

· On-Board Chargers (OBCs): Efficiently charge electric vehicle batteries.

· DC-DC Converters: Regulate voltage in EVs and hybrid vehicles.

· Motor Drive Inductors: Improve efficiency in electric and hybrid vehicle powertrains.

High-Frequency Filtering & Signal Processing

· RF Inductors: Used in telecommunications and signal filtering.

· Magnetic Sensors: Enhance precision in measuring systems.

Nanocrystalline Cores vs. Other Magnetic Core Materials

Nanocrystalline cores provide superior magnetic properties and are essential for high-frequency, high-efficiency power applications. Their ability to reduce core losses, improve power density, and enhance EMI suppression makes them the preferred choice in modern electronics, automotive, renewable energy, and power electronics applications.

If you need further information or specific recommendations on nanocrystalline cores, let us know!

ESSEN can provide below nanocrystalline cores:

NDC-NANO

Features:

• Anti electromagnetic interference
• High magnetic permeability Low loss
• Very Stable temperature characteristics

Application:

Suitable for common mode filtering products with requirements for resisting DC components and transformer iron cores with high stability and low loss.

Dimension & Performance:

NOC-NANO

Features:

• Anti electromagnetic interference
• High magnetic permeability Low loss
• Very Stable temperature characteristics

Application:

Suitable for common mode filtering products with requirements for resisting DC components and transformer iron cores with high stability and low loss.

Dimension & Performance:

NRC-NANO

Features:

• Anti electromagnetic interference
• High magnetic permeability Low loss
• Very Stable temperature characteristics

Application:

Suitable for common mode filtering products with requirements for resisting DC components and transformer iron cores with high stability and low loss.

Dimension & Performance:

NTC-NANO

Features:

• Anti electromagnetic interference
• High magnetic permeability Low loss
• High stability

Application:

High precision transformer and transformer field.