Optimizing Performance: Advanced Techniques in Cylindrical Magnet Design

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Welcome to the world of cylindrical magnets, where seemingly simple shapes unlock complex possibilities! If you’re looking to take your magnet applications to the next level, you’ve landed in the right place. This article isn’t just another overview; it’s your deep dive into Optimizing Performance: Advanced Techniques in Cylindrical Magnet Design. We’ll explore how to squeeze every ounce of performance from these workhorse magnets, from material selection to cutting-edge design strategies. Ready to become a cylindrical magnet expert? Let’s get started!

What Key Performance Metrics Should You Focus on in Cylindrical Magnet Design?

When we talk about "performance" in magnets, what exactly are we measuring? It’s not just about how strongly a magnet sticks to your fridge! For cylindrical magnets, several key metrics dictate how well they perform in their intended application. Understanding these metrics is the first step towards optimization.

Firstly, magnetic flux density, often measured in Tesla (T) or Gauss (G), is crucial. This tells you the strength of the magnetic field the magnet produces. A higher flux density generally means a stronger magnet. Think of it like the horsepower of a car – it indicates the power available.

Secondly, consider coercitività. This is a magnet’s resistance to demagnetization – its ability to withstand external magnetic fields or temperature changes without losing its magnetic strength. High coercivity is vital for magnets used in harsh environments or those needing to maintain consistent performance over time. It’s like the resilience of a material, how well it holds up under stress.

Finally, energy product is a comprehensive measure of a magnet’s overall strength. It combines remanence (how much magnetization remains after the magnetizing field is removed) and coercivity, giving you a single value that reflects the magnet’s ability to do work. A higher energy product generally translates to a more compact yet powerful magnet, which is often desirable in many applications.

How Does Material Choice Significantly Impact Cylindrical Magnet Performance?

The material you choose is the bedrock of your cylindrical magnet’s performance! Different magnetic materials offer vastly different properties, leading to diverse strengths, temperature stabilities, and costs. Selecting the right material is often the most impactful decision in magnet design.

Neodymium (NdFeB) magnets are the rock stars of the magnet world. They offer the highest energy product among commercially available magnets, meaning they are incredibly strong for their size. This makes them ideal for applications where powerful magnetism is needed in a compact form, such as in motors, sensors, and medical devices. However, they can be more susceptible to temperature changes and corrosion compared to other materials.

Ferrite magnets, also known as ceramic magnets, are the workhorses. They may not be as powerful as neodymium magnets, but they are significantly cheaper, have good corrosion resistance, and perform well at higher temperatures. Ferrites are excellent for applications where cost is a major constraint and extreme magnetic strength isn’t paramount, like in loudspeakers, magnetic separators, and holding magnets.

Samarium Cobalt (SmCo) magnets bridge the gap between neodymium and ferrite in some aspects. They offer excellent temperature stability and good corrosion resistance, even exceeding ferrites in temperature performance. While not as powerful as neodymium, they are stronger than ferrites and maintain their magnetism exceptionally well in demanding conditions. This makes them suitable for aerospace, military, and high-temperature applications.

Alnico magnets, composed of aluminum, nickel, and cobalt, represent a more traditional option. They boast excellent temperature stability, even better than SmCo in some cases, and good corrosion resistance. However, they are not as strong as neodymium or samarium cobalt and are more easily demagnetized. Alnico magnets find applications in sensors, meters, and specialized holding magnets where high temperature operation is critical.

Esempio:

Imagine you’re designing a small, powerful motor for a drone. Neodymium magnets would likely be your top choice due to their high energy product, allowing for a smaller, lighter motor while delivering strong performance. On the other hand, if you are designing a large magnetic separator for recycling and cost is a primary concern, ferrite magnets would be a more economical and practical solution.

Can Optimizing Cylindrical Magnet Geometry Alone Boost Magnetic Field Strength?

Absolutely! While material is fundamental, the geometry of a cylindrical magnet plays a critical role in shaping and maximizing its magnetic field. It’s not just about having the right material; it’s about sculpting it effectively! Small tweaks to dimensions can lead to significant improvements in performance.

Consider the length-to-diameter ratio of a cylindrical magnet. A long, thin cylinder will behave differently than a short, squat cylinder made of the same material. Longer magnets tend to produce a stronger magnetic field along their axis, extending further out from the ends. Shorter, wider magnets, on the other hand, might concentrate the magnetic field closer to their faces.

Chamfering or rounding the edges of a cylindrical magnet can also impact field distribution. Sharp edges can create areas of concentrated magnetic flux and potentially introduce stress points. Rounded edges can help to smooth out the magnetic field and improve overall performance in certain applications.

Think about magnetic pole shaping. While cylindrical magnets naturally have poles at their ends, the precise shape of these poles can be modified slightly, particularly in more complex, multi-pole designs (though typically less relevant for simple cylinders). For example, subtly contouring the pole faces might optimize the field profile for a specific sensor application, making it more sensitive or focused.

Visualizing the impact of geometry:

Imagine two cylindrical magnets made of the same material and volume:

• Magnet A: Long and thin (Length: Diameter ratio = 5:1) – Strong focused field along the axis, extends far. Excellent for long-range sensing applications.
• Magnet B: Short and wide (Length: Diameter ratio = 1:2) – Stronger field closer to the faces, less extension along the axis. Better for holding applications where close proximity is key.

By carefully adjusting the dimensions and shape, even within the constraints of a cylindrical form, designers can fine-tune the magnetic field characteristics to match specific application needs, often without changing the underlying magnetic material.

What Advanced Magnet Materials Are Emerging for Enhanced Performance?

While neodymium, ferrite, SmCo, and alnico are mainstays, the quest for even better magnetic performance constantly pushes material science forward. Several advanced magnet materials are emerging, promising to redefine the limits of cylindrical magnet design.

High-performance Neodymium Magnets: Research continues to refine neodymium magnets, pushing their energy product even higher and improving their temperature stability. Doping with elements like Dysprosium and Terbium has traditionally been used to enhance high-temperature performance, although efforts are underway to reduce the reliance on these heavy rare earth elements due to cost and supply chain concerns. Newer approaches focus on grain boundary engineering and novel alloying to achieve similar or better results with less or no heavy rare earths.

Bonded Magnets: Instead of sintered magnets which are dense and brittle, bonded magnets are made by embedding magnetic particles in a polymer or resin matrix. This allows for more complex shapes and finer tolerances through injection molding or compression molding. While bonded magnets generally have lower energy products than sintered magnets of the same material, advancements in particle technology and bonding materials are closing this gap. They are particularly useful for creating intricate magnetic assemblies and are often more cost-effective for complex shapes.

Nanocomposite Magnets: Nanotechnology is making waves in magnetics. Nanocomposite magnets combine different magnetic phases at the nanoscale level to achieve properties that are superior to conventional single-phase magnets. Exchange-coupled nanocomposite magnets, for instance, aim to combine high-remanence and high-coercivity phases to maximize energy product. While still largely in the research and development phase, nanocomposite magnets hold immense potential for future high-performance applications.

Magneti senza terre rare: The dependence on rare earth elements, particularly for neodymium magnets, has spurred research into alternative materials. Materials like iron nitrides e manganese bismuth are being explored as potential high-performance, rare earth-free magnets. While these are less mature than neodymium magnets and face challenges in manufacturing and performance consistency, breakthroughs in this area could revolutionize the magnet industry by reducing reliance on critical rare earth elements.

Statistiche: The global market for magnetic materials is projected to grow significantly in the coming years, driven by increasing demand in electric vehicles, renewable energy, and consumer electronics. The development of advanced magnet materials is crucial to meet these growing demands and address challenges related to performance, cost, and sustainability. For example, research efforts in nanocomposite and rare earth-free magnets are showing promising results, with some initial prototypes demonstrating energy products approaching those of conventional ferrite magnets while reducing or eliminating the use of rare earths.

How Do Temperature Variations Affect Cylindrical Magnet Performance and Longevity?

Temperature is a critical environmental factor that significantly impacts cylindrical magnet performance and longevity. Magnets are not immune to heat and cold; their magnetic properties can change, sometimes dramatically, with temperature fluctuations.

Curie Temperature: Every ferromagnetic material has a Curie temperature. This is the temperature above which the material loses its ferromagnetism and becomes paramagnetic. For permanent magnets, exceeding the Curie temperature is generally catastrophic, as the magnet will largely lose its magnetization and may not recover fully upon cooling. Different magnet materials have different Curie temperatures. For example, neodymium magnets typically have lower Curie temperatures than ferrite or alnico magnets, making them more sensitive to heat.

Reversible Temperature Coefficient: Even below the Curie temperature, magnetic properties like remanence and coercivity change with temperature. The reversible temperature coefficient describes the percentage change in a magnetic property per degree Celsius (or Kelvin). For most permanent magnet materials, remanence decreases as temperature increases, while coercivity may increase or decrease depending on the material. This reversible change is generally predictable and can be accounted for in design, especially for applications operating over a wide temperature range.

Irreversible Losses: Exposure to elevated temperatures, even below the Curie temperature, can sometimes cause irreversible losses in magnetization. This is particularly true for neodymium magnets. These irreversible losses happen because the magnetic domains within the material can become slightly rearranged at higher temperatures, even if the material does not fully demagnetize. Careful magnet selection and operating temperature considerations are crucial to minimize irreversible losses.

Impact on Applications: Consider a cylindrical magnet used in a motor operating in a high-temperature environment, like an electric vehicle engine. If neodymium magnets are chosen without careful consideration, the motor’s performance could degrade significantly as the magnets heat up. In such cases, selecting a more temperature-stable material like samarium cobalt or even designing with cooling strategies might be necessary.

Diagramma:

[Diagram would be here]

Title: Effect of Temperature on Magnetic Properties
X-axis: Temperature (°C)

Y-axis: Magnetic Property (e.g., Remanence, Coercivity)
Curves showing:

- Remanence decreasing with increasing temperature (for NdFeB)

- Coercivity changing (could be increasing or decreasing depending on material)

- Curie Temperature clearly marked where magnetization drops to near zero.

(Imagine a chart visually representing the temperature dependence of magnetic properties. This would be a helpful visual element here.)

Is Demagnetization a Significant Risk in Cylindrical Magnet Applications, and How Can It Be Prevented?

Smagnetizzazione is a real threat to the performance and reliability of cylindrical magnets in many applications. It refers to the partial or complete loss of magnetization. Understanding demagnetization risks and employing preventative measures is crucial for robust magnet design.

External Demagnetizing Fields: Magnets are susceptible to demagnetization when exposed to external magnetic fields that oppose their own magnetization direction. These demagnetizing fields can come from nearby magnets, current-carrying conductors, or even the geometry of the magnetic circuit itself. The shape and orientation of a cylindrical magnet within its application greatly influence its susceptibility to external demagnetizing fields. For example, a very short cylindrical magnet might have a stronger internal demagnetizing field component due to its geometry.

Temperature-Induced Demagnetization: As discussed earlier, elevated temperatures can increase the risk of demagnetization, especially for materials with lower Curie temperatures or high-temperature coefficients. The combination of high temperature and external demagnetizing fields can be particularly detrimental.

Impact of Geometry on Demagnetization: Il shape and aspect ratio of a cylindrical magnet influence its internal demagnetizing field. Short, squat cylinders tend to have stronger internal demagnetizing fields compared to long, thin cylinders of the same volume. This means that shorter magnets are generally more susceptible to demagnetization.

Preventing Demagnetization:

• Material Selection: Choose magnet materials with high coercivity for applications where demagnetization is a concern. Samarium cobalt and alnico magnets, for instance, offer superior resistance to demagnetization compared to some grades of neodymium magnets.
• Optimized Magnetic Circuit Design: Carefully design the magnetic circuit to minimize external demagnetizing fields acting on the magnet. This might involve using soft magnetic materials to shield the magnet or shaping the surrounding ferromagnetic components to guide the flux and reduce stray fields.
• Temperature Management: Control the operating temperature of the magnet as much as possible. This might involve heat sinks, cooling fans, or choosing materials with higher Curie temperatures for high-temperature applications.
• Operating Point Considerations: In magnetic circuit design, the “operating point” of the magnet on its demagnetization curve is crucial. Designing the circuit to ensure the magnet operates well above the “knee” of the demagnetization curve provides a safety margin against demagnetization.

Caso di studio:

Consider a cylindrical magnet used in a magnetic coupling in a chemical pump. This pump might operate with hot fluids and potentially experience strong external magnetic fields from nearby machinery. Simply choosing a very strong neodymium magnet might not be sufficient. A robust design would involve:

1. Selecting a high-coercivity grade of neodymium magnet, or even SmCo for better temperature resistance.
2. Designing the housing of the magnetic coupling to shield the magnet from external fields.
3. Incorporating cooling features if necessary to keep the magnet operating within its safe temperature range.
4. Carefully analyzing the magnetic circuit to ensure the magnet operates at a safe point on its demagnetization curve, even under worst-case operating conditions.

What Role Does Finite Element Analysis (FEA) Play in Advanced Cylindrical Magnet Design?

Finite Element Analysis (FEA) is an indispensable tool in modern, advanced cylindrical magnet design. It’s like having a virtual lab where you can test and refine your magnet designs before ever building a physical prototype. FEA allows engineers to simulate complex magnetic behaviors with incredible accuracy.

Predicting Magnetic Field Distribution: FEA software solves complex mathematical equations to predict the magnetic field distribution around a cylindrical magnet in various configurations. This includes visualizing flux lines, calculating flux density at any point in space, and understanding how the field interacts with surrounding components. This level of detail is often impossible to achieve through analytical calculations alone, especially for complex geometries or magnetic circuits.

Optimizing Magnet Geometry: FEA enables iterative design optimization. Engineers can modify the geometry of a cylindrical magnet or its surrounding components within the FEA model and instantly see how these changes affect the magnetic field performance. This allows for rapid exploration of design alternatives to maximize field strength, uniformity, or other desired performance metrics, as we discussed earlier with length-to-diameter ratios and edge shaping.

Analyzing Demagnetization Risk: FEA software can simulate the effects of external demagnetizing fields and temperature changes on a cylindrical magnet. By modeling the magnet’s operating environment, engineers can identify potential demagnetization risks and adjust the design (material, geometry, magnetic circuit) to mitigate these risks before fabrication. FEA can essentially "stress-test" your magnet design virtually.

Designing Magnetic Circuits: Cylindrical magnets are rarely used in isolation. They are typically part of a larger magnetic circuit involving other magnets, ferromagnetic components (steel, iron), air gaps, and coils. FEA is essential for designing and optimizing these magnetic circuits. It can simulate the entire system, ensuring efficient flux flow, predicting forces and torques, and verifying overall performance.

Example of FEA Application:

Imagine designing a cylindrical magnet-based sensor to detect small changes in magnetic field. Using FEA, you could:

1. Model different cylindrical magnet geometries and materials to see which produces the most sensitive and uniform magnetic field in the sensing region.
2. Simulate the effect of nearby ferromagnetic structures on the sensor’s performance and optimize their placement to enhance sensitivity or shield against unwanted interference.
3. Analyze the impact of temperature changes on the sensor’s output signal and design temperature compensation strategies.
4. Virtually "test" the sensor under various operating conditions (different magnetic field strengths, temperatures, vibration) to ensure it meets performance requirements before building a physical prototype.

Diagramma:

[Diagram would be here]

Title: FEA Simulation of Cylindrical Magnet Field
Image: A screenshot or simplified representation of an FEA simulation.

Showing:

- A cylindrical magnet in cross-section.

- Color contours representing magnetic flux density distribution around and inside the magnet.

- Magnetic flux lines emanating from the magnet and looping back.

- Potentially a nearby ferromagnetic component influencing the field.

(A visual representation of an FEA simulation output would be very helpful here, illustrating the magnetic field around a cylindrical magnet.)

How Can We Balance High Performance with Cost-Effectiveness in Cylindrical Magnet Design?

Achieving peak performance is desirable, but efficacia dei costi is often equally, if not more, important in real-world cylindrical magnet applications. Striking the right balance between performance and cost is a key challenge in magnet design. It’s about getting the most "bang for your buck".

Strategic Material Selection: As we discussed earlier, different magnet materials have vastly different costs. Neodymium magnets offer the highest performance but are generally more expensive than ferrite magnets. Carefully consider the performance requirements of your application. If you don’t need the absolute strongest magnet possible, ferrite magnets might provide a sufficiently good performance at a significantly lower cost. Using a less expensive grade of neodymium, where slightly reduced performance is acceptable, is another strategy.

Optimizing Geometry for Material Efficiency: Clever geometric design can sometimes reduce the amount of magnet material needed to achieve a specific performance level. For example, carefully shaping pole pieces or using flux concentrators made of soft magnetic materials can help focus the magnetic flux, achieving a stronger field in the desired area with a smaller magnet volume. FEA is invaluable for exploring these geometry optimizations.

Standardization and Off-the-Shelf Magnets: Whenever possible, consider using standard, off-the-shelf cylindrical magnet sizes and grades. Custom-designed magnets often come with higher tooling and manufacturing costs. Utilizing readily available magnets reduces lead times and typically lowers per-unit cost due to economies of scale. Check magnet supplier catalogs first before considering a custom design.

Tolerance Management: Tighter tolerances in magnet manufacturing increase cost. Analyze the tolerance requirements of your application. Can you relax tolerances on certain dimensions or magnetic properties without significantly impacting performance? Looser tolerances can often lead to cost savings, especially in high-volume production.

Considering Manufacturing Processes: Different magnet materials and shapes have different manufacturing processes with varying costs. Sintered magnets are more expensive to manufacture in complex shapes compared to bonded magnets. Injection molding of bonded magnets can be very cost-effective for complex geometries in large quantities. The choice of manufacturing process can significantly impact overall cost.

Example – Cost Optimization Scenario:

Imagine you’re designing a simple magnetic door latch. High magnetic strength is not critical, but cost and corrosion resistance are important. In this case:

1. Material Choice: Ferrite magnets would be an excellent choice due to their low cost and good corrosion resistance. Neodymium magnets would be overkill and unnecessarily expensive.
2. Geometry: A simple cylindrical shape is likely sufficient. No need for complex geometries or specialized features.
3. Standard Sizes: Utilize readily available standard size ferrite cylinders to minimize cost and lead time.
4. Tolerances: Relaxed tolerances are acceptable for a door latch. No need for tight precision.
5. Produzione: Ferrite magnets are mass-produced and cost-effective to manufacture in basic shapes.

By carefully considering these factors, you can design a functional and cost-effective magnetic door latch without using premium, expensive magnet materials or complex designs.

What Innovative Applications Are Driving Advanced Cylindrical Magnet Design?

Innovation never sleeps, and new applications are constantly emerging, pushing the boundaries of advanced cylindrical magnet design. These applications demand higher performance, smaller sizes, greater efficiency, and novel functionalities, driving continuous advancements in magnet technology.

Veicoli elettrici (EV): The rapid growth of the EV market is a major driver for magnet innovation. Electric motors in EVs rely heavily on high-performance permanent magnets, primarily neodymium magnets, for efficiency and power density. The demand for EVs is pushing the development of even stronger, more temperature-stable, and potentially rare earth-reduced magnets to improve motor performance, range, and cost-effectiveness.

Renewable Energy (Wind Turbines): Large direct-drive wind turbines often utilize permanent magnet generators for higher efficiency and reliability. Cylindrical segments of powerful magnets are crucial components in these generators. Larger and more efficient wind turbines require increasingly powerful and robust magnets, driving innovation in high-performance and large-scale magnet manufacturing.

Dispositivi medici: Cylindrical magnets are used in various medical devices, including MRI machines, drug delivery systems, and surgical instruments. Advancements in medical technology demand smaller, more precise, and biocompatible magnets. Miniaturization and specialized magnetic properties (e.g., precisely controlled magnetic fields for focused drug delivery) are key areas of innovation.

Robotics and Automation: Robotics, from industrial robots to collaborative robots (cobots), and automation systems rely on magnets in motors, sensors, and actuators. Demand for more agile, precise, and energy-efficient robots is driving the need for advanced magnets that are lighter, stronger, and more controllable.

Elettronica di consumo: Despite their small size, cylindrical magnets often find applications in consumer electronics, from speakers to headphones to smartphones. Miniaturization, high audio quality, and low power consumption in these devices are driving demand for tiny yet powerful magnets with precisely tailored magnetic characteristics.

Emerging Applications: Beyond these established areas, new applications are constantly emerging, including:

• Magnetic Refrigeration: A potentially more energy-efficient and environmentally friendly alternative to conventional vapor compression refrigeration, relying on magnetocaloric materials and strong magnetic fields.
• Magnetic Levitation (Maglev): High-speed trains and other transportation systems utilizing magnetic levitation require powerful and precisely controlled magnetic forces.
• Fusion Energy: Confining plasma in fusion reactors often relies on powerful magnetic fields generated by superconducting magnets, and advancements in permanent magnet technology may contribute to future fusion reactor designs.

Statistiche e fatti:

• The EV market is predicted to grow exponentially in the coming decade, fueling demand for high-performance magnets.
• The wind energy sector is also expanding rapidly, requiring larger and more efficient wind turbines with advanced magnet generators.
• Research and development spending in magnetic materials is increasing globally, focusing on new materials, improved performance, and reduced reliance on rare earth elements.

Can Pulsed Magnetization Techniques Enhance the Performance of Cylindrical Magnets?

Pulsed magnetization techniques offer a fascinating avenue for potentially enhancing the performance of cylindrical magnets, especially for certain applications. Instead of applying a static magnetic field to magnetize the material, pulsed magnetization uses short, intense bursts of magnetic field.

Achieving Saturation Magnetization: For some magnet materials, particularly high-coercivity materials, achieving full saturation magnetization (the maximum possible magnetization) with a static magnetic field can be challenging and require very strong and costly magnetizing equipment. Pulsed magnetization can overcome this limitation by delivering a very high magnetic field for a short duration. This intense pulse can more effectively align the magnetic domains within the material, potentially resulting in higher remanence and a stronger overall magnet.

Faster Magnetization Process: Pulsed magnetization is a much faster process than traditional static magnetization. The short duration of the pulse means magnets can be magnetized very quickly, which can be advantageous in high-volume manufacturing environments. This speed can translate to efficiency gains in production.

Complex Magnetization Patterns: Beyond simply magnetizing a magnet to saturation, pulsed magnetization techniques can also be used to create more complex magnetization patterns within cylindrical magnets. By carefully controlling the shape, duration, and spatial distribution of the pulsed magnetic field, it is possible to create multi-pole magnets or other specialized magnetization profiles within a single cylindrical magnet. This opens up possibilities for advanced sensors and actuators with tailored magnetic characteristics.

Limitations and Considerations:

• Equipment Complexity and Cost: Pulsed magnetization equipment can be more complex and expensive than static magnetizers. Generating very high current pulses requires specialized power supplies and coil designs.
• Material Suitability: Pulsed magnetization is not equally effective for all magnet materials. It is generally more beneficial for high-coercivity materials where achieving saturation magnetization with static fields is difficult. For materials that easily saturate, pulsed magnetization may not offer significant advantages.
• Thermal Effects: The high current pulses used in pulsed magnetization can generate significant heat. Cooling strategies may be necessary to prevent overheating the magnet and surrounding equipment, particularly in repeated pulse applications.

Future Potential: Research into pulsed magnetization techniques is ongoing, with efforts to improve efficiency, reduce equipment cost, and explore new applications. As pulsed magnetization technology matures, it may become a more widely adopted technique for enhancing the performance and expanding the capabilities of cylindrical magnets, particularly in specialized applications requiring high performance or complex magnetization patterns.

Frequently Asked Questions (FAQs) About Cylindrical Magnet Design

What is the strongest type of cylindrical magnet available?

Neodymium magnets are generally considered the strongest type commercially available in cylindrical form. They boast the highest energy product, meaning they offer the most powerful magnetic field for their size compared to other common magnet materials like ferrite, samarium cobalt, or alnico. Specific grades of neodymium magnets further differentiate their strength, with higher grades offering even greater magnetic performance. However, "strongest" can sometimes be subjective, depending on the specific metric you prioritize. If temperature stability is paramount, for example, samarium cobalt might be considered "stronger" in high-temperature applications despite having a lower energy product than top-grade neodymium.

How do I calculate the magnetic force of a cylindrical magnet?

Calculating the precise magnetic force of a cylindrical magnet can be complex and often requires numerical methods like Finite Element Analysis (FEA), especially in realistic scenarios with complex geometries and ferromagnetic components. However, for simplified scenarios in free space, approximate formulas exist. Factors influencing the force include the magnet’s material (remanence), dimensions (surface area, length), and the distance to the object it’s attracting. Online calculators and magnet design software can provide estimates. For accurate force calculations in real-world applications, FEA simulation is highly recommended.

What are the common applications of cylindrical magnets?

Cylindrical magnets are incredibly versatile and found in a wide range of applications. Some common examples include:

• Motori e generatori elettrici: As rotor magnets.