Glossary of magnetic terminology
How to navigate the world of neodymium magnets?
Hello to our extensive glossary centered around the fascinating world of neodymium magnets. As a recognized supplier in providing top-notch magnetic solutions, we are aware of how important it is to have a reliable information about the basic notions in this unique field. This glossary has been meticulously prepared to serve as an valuable source of information for all those interested who is curious about magnets – whether you are an specialist, a hobbyist, or a person intrigued by the knowledge of magnets.
In our glossary, you will find clear and thorough explanations of key terms and subjects related to neodymium magnets. From the principles of magnetic fields and magnetic induction, to material characteristics and magnet types, each definition has been designed to expand your understanding and make accessible even the most complex ideas. Regardless of whether you are studying industrial applications, performing DIY projects, or simply curious magnetism, this glossary aims to support your learning.
Explore the captivating world of neodymium magnets effortlessly. Broaden your understanding, gain fresh perspectives, and unlock the potential of these exceptional materials, understanding terms and concepts that influence their versatility and utility. Use this glossary your guide in delving into the developing domain of magnetic technology.
Litera: A
The air gap is the distance or another non-magnetic material that separates a magnet from another object. A larger air gap weakens the magnetic field. Formula: B = μ0(H - M), where:
B - magnetic induction,
μ0 - permeability of free space,
H - magnetic field strength,
M - magnetization.
B - magnetic induction,
μ0 - permeability of free space,
H - magnetic field strength,
M - magnetization.
An anisotropic material, such as neodymium magnets, has properties that vary with direction. Anisotropic magnets are stronger than isotropic magnets, but they can only be magnetized along a specific axis.
Annealing is a method for relieving internal stresses in magnetic materials. It is performed at high temperatures, usually in a vacuum to prevent material degradation. Annealing improves the structure and allows the material to be tailored to application requirements.
Axial magnetization means that the magnetic poles are distributed along the axis of the magnet, and the magnetic field lines run parallel to its axis. This configuration is commonly used in ring-shaped and ball-shaped magnets. Formula: Bz = (Br/2) × [(L + 2z) / (L² + 4z²)0.5 - (L - 2z) / (L² + 4z²)0.5].
Litera: B
Magnetic induction B is the amount of magnetic flux passing through a surface. It is measured or gauss. Formula: B = μ0(H + M), where:
μ0 - permeability of free space,
H - applied magnetic field,
M - magnetization.
μ0 - permeability of free space,
H - applied magnetic field,
M - magnetization.
The hysteresis loop is a chart of the relationship between magnetic induction (B) and field strength. It helps determine properties like magnetic energy loss. The hysteresis loop is essential in evaluating materials used in transformers.
Remanent induction Bd is the remaining magnetization in a material after the external magnetic field is removed. It is measured in teslas and represents the material's ability to maintain residual magnetization.
The slope of the operating line, denoted as Bd/Hd, is the ratio of remanent induction to demagnetizing force. Formula: Bd/Hd = (Br - Hd) / Hd. This is a key parameter in the design of electromagnetic systems.
Bg represents the average magnetic induction in the air gap. It is a critical parameter in designing devices such as sensors and actuators. Formula: Bg = Φ / A, where:
Φ - magnetic flux,
A - air gap area.
Φ - magnetic flux,
A - air gap area.
Litera: C
The C.G.S. system of units is primarily used in magnetism for describing material properties. Despite being succeeded by the MKSA (SI) system, C.G.S. is still relevant in historical and specialized analyses. This system includes units for as well as length, mass, and time.
A closed circuit refers to a configuration where there are no breaks or interruptions. It uses magnetic components to ensure continuity of magnetic field flow. Such circuits are essential in applications requiring controlled magnetic fields.
Coercive force, denoted as Hc, is the field intensity required to demagnetize a material. This parameter measures the material's resistance to demagnetization. Formula: Hc = -M/χ, where:
M - magnetization,
χ - magnetic susceptibility.
M - magnetization,
χ - magnetic susceptibility.
Coercivity measures a magnetic material's resistance to demagnetization. This parameter is critical in designing permanent magnets for motors and generators.
Intrinsic coercivity, denoted as Hci or iHc, represents the ability to maintain its magnetic properties. It measures the demagnetizing force acting on intrinsic induction (Bi). Materials with high coercivity exhibit long-lasting magnetic characteristics.
Curie temperature is the point at which transition to a paramagnetic state. Beyond this temperature, the material ceases to exhibit strong magnetic behavior. Formula: Tc = (2kB / μ0) × J02 / χ, where:
kB - Boltzmann constant,
J0 - magnetic moment.
kB - Boltzmann constant,
J0 - magnetic moment.
Litera: D
Demagnetization refers to the process of weakening residual induction in a material. Methods include applying alternating magnetic fields, heating above the Curie temperature. This process is essential in applications requiring precise control of magnetization.
The demagnetization curve illustrates the relationship through cycles of magnetization and demagnetization. It reveals the material's hysteresis characteristics, including stability of magnetic properties. This tool is commonly used in designing magnetic circuits.
Demagnetization force refers to the opposing magnetic field that induces demagnetization. This force allows for manipulating magnetic properties.
A demagnetized material is one where all residual magnetization has been removed. This state is achieved through or other demagnetization techniques such as heating. Demagnetization is important in eliminating unwanted magnetic effects.
approximately 7.5 g/cm³, is one of the key parameters defining its magnetic properties. Density can be approximately determined using the formula:
ρ = m / V, where:
ρ - density (in g/cm³ or kg/m³),
m - mass of the magnet (in grams or kilograms),
V - volume of the magnet (in cm³ or m³).
Consider a magnet with a mass of 150 g and a volume of 20 cm³, the density is:
ρ = 150 / 20 = 7.5 g/cm³.
Knowing the density helps predict the magnet's strength and durability.
ρ = m / V, where:
ρ - density (in g/cm³ or kg/m³),
m - mass of the magnet (in grams or kilograms),
V - volume of the magnet (in cm³ or m³).
Consider a magnet with a mass of 150 g and a volume of 20 cm³, the density is:
ρ = 150 / 20 = 7.5 g/cm³.
Knowing the density helps predict the magnet's strength and durability.
Diamagnetic materials exhibit no permanent magnetic moment. When exposed to an external field, they produce a repelling effect. This behavior results from induced currents within the material.
Diameter refers to the measured in a straight line across the surface of a disc, ring, or spherical magnet. It is a critical parameter in designing magnetic systems.
Diametrically magnetized magnets have creating a circular magnetic field pattern. They are commonly used in applications requiring unique magnetic field configurations.
Dimensional tolerance specifies the range of variation in magnet size. It is crucial for precise fitting.
Dimensions refer to the measurable physical properties of a magnet. Precision in measurements is key to ensuring the proper functionality of magnetic systems.
The direction of magnetization defines the path along which the magnetic field is established. This is a critical feature that affects the material's magnetic behavior.
Domains are microscopic regions where creating localized magnetic fields. They can be altered by external magnetic fields, temperature, or stress.
Litera: E
Eddy currents are electrical currents induced in conductive materials when exposed to changing magnetic fields. They cause efficiency issues. The use of optimized designs minimizes their impact and enhances performance.
An electromagnet is a magnet that relies on an electric coil to produce a magnetic field. The strength of the magnetic field depends on the current. Electromagnets are widely used in industries and technologies.
The energy product is an indicator of a magnet's ability to supply energy. It is calculated as the multiplication of two parameters from the demagnetization curve. Expressed in MGOe (Mega Gauss Oersteds) or kJ/m³, it is an essential measure for evaluating their efficiency in applications.
Measured as the product of the material's remanence and coercivity. This parameter is essential in evaluating the performance and strength of a magnet in industrial applications.
Litera: F
Ferrites are substances primarily composed of iron oxide (Fe2O3). They combine low electrical conductivity with high magnetic permeability. Used in applications requiring low eddy current losses.
A ferromagnetic material is characterized by its ability to amplify magnetic flux. In such materials, atoms align parallel under an external magnetic field. Examples include iron, nickel, cobalt. They are widely used due to their permanent magnetic properties.
Flux density, denoted as B, defines the strength of the magnetic field. Measured in standard magnetic units, it is a crucial parameter for designing magnetic systems.
A fluxmeter is used to measure magnetic induction (B). It employs various technologies such as the Hall effect or rotating coil techniques. It is essential for diagnostics and design.
Litera: G
Gauss is a unit of magnetic induction. One Gauss (G) equals 10^-4 Tesla (T). Commonly used in laboratory applications.
A Gauss meter is a device for measuring magnetic field strength. It uses Hall effect sensors. It is used in many branches of engineering and science.
The Gilbert is named after William Gilbert, a pioneer in magnetic research. One Gilbert represents an older measure now replaced by ampere-turns (At) in the SI system.
The grade of a magnet refers to performance and suitability for specific applications. Higher grades offer greater resistance to temperatures and demagnetizing forces.
Litera: H
Used for measuring magnetic fields and detecting position. Hall sensors are widely utilized in electronics, such as ABS systems in vehicles.
Coercive force (Hc) represents a measure of a material's resistance to demagnetization. Expressed in oersteds (Oe) or kiloamperes per meter (kA/m), higher Hc values indicate resistance to external influences.
Hd denotes the force needed to magnetize a material and retain that state after the field is removed. Measured in various magnetic units.
A high field gradient magnet produces strong and rapidly changing magnetic fields. Applications include MRI, magnetic separation.
Hm represents the maximum applied magnetic field strength before a material reaches saturation. It is critical for designing systems requiring high magnetic fields.
A homogeneous field is characterized by a lack of intensity variations over a given area. It is such as spectroscopy or device calibration.
A horseshoe magnet has its poles placed close together. and applications requiring focused magnetic fields.
Net effective magnetizing force (Hs) refers to the field needed to fully magnetize a material to saturation. Measured in oersteds (Oe) or kiloamperes per meter (kA/m).
The hysteresis graph, also called a permeameter, illustrates changes in magnetic induction (B) as a function of magnetizing force (H). It is used in quality control, energy loss analysis.
The hysteresis loop is a graphical representation of the relationship between magnetic induction (B) and magnetizing force (H). It provides information about energy losses, coercivity, and energy storage capacity.
Hysteresis refers to a characteristic of magnetic materials. Hysteresis loss is the energy lost as heat during magnetization and demagnetization cycles. Minimizing hysteresis loss improves the efficiency of magnetic systems.
Litera: I
Inner diameter (ID) refers to the internal dimension of a hollow object, such as a magnet, tube, or ring. It is an essential parameter in magnetic circuit design.
Magnetic induction (B) represents the amount of magnetic flux passing through a unit area. It is measured in Teslas (T) or Gauss (G). Essential for designing and analyzing magnetic systems.
Irreversible losses refer to the effects of high temperatures, mechanical stress, or demagnetizing fields. They result in a decrease in magnetic properties and performance.
An isotropic material is independent of magnetic field orientation. Often compared to anisotropic materials with direction-dependent properties.
Litera: K
A keeper is an accessory preventing demagnetization of magnets. It provides a low magnetic resistance path for flux. Used primarily with Alnico magnets or older designs.
Kilogauss (kG) is a unit used to express magnetic induction or flux density. 1 kilogauss = 1000 Gauss. Commonly used in scientific research, magnet testing.
Litera: L
The load line represents the operating points of a magnetic material on the demagnetization curve. useful for optimizing magnetic applications.
Lodestone is a naturally occurring magnetic material composed of iron oxide (Fe3O4). Historically used for compasses.
Litera: M
A magnet is an object producing a magnetic field with magnetic poles. widely used in electronics, motors, generators, and magnetic storage devices.
A magnetic assembly is designed to achieve specific magnetic properties. and magnetic levitation systems.
The magnetic axis is the preferred path of magnetic flux. It connects the poles of the magnet and defines the orientation of its magnetic field.
A magnetic circuit is a path through which magnetic flux flows. Comprises magnetic materials, air gaps, and other components.
Magnetic energy is the energy stored within a magnetic field. Important in applications like magnetic resonance imaging or magnetic generators.
A magnetic field (B) is a fundamental electromagnetic phenomenon. Represented by magnetic flux lines.
Magnetic field strength (H) is a measure of the magnetizing force applied to a magnetic material. expressed in amperes per meter (A/m).
Magnetic flux is a measure of the total magnetic field in a given region. Expressed in webers (Wb).
Magnetic flux density, denoted as B, is a parameter describing the intensity of the magnetic field at a specific location. It represents the number of magnetic field lines intersecting a surface.
The equation for it is:
B = Φ / A
Where:
B: Magnetic flux density (Tesla, Gauss)
Φ: Magnetic flux (Weber)
A: Surface area (m²)
For example, with a magnetic flux of 0.01 Weber and an area of 0.1 m², the magnetic flux density is 0.1 Tesla.
Magnetic flux density is critical for designing devices like motors, generators, or magnetic sensors.
The equation for it is:
B = Φ / A
Where:
B: Magnetic flux density (Tesla, Gauss)
Φ: Magnetic flux (Weber)
A: Surface area (m²)
For example, with a magnetic flux of 0.01 Weber and an area of 0.1 m², the magnetic flux density is 0.1 Tesla.
Magnetic flux density is critical for designing devices like motors, generators, or magnetic sensors.
Provides key data such as remanence and coercivity. Materials with a narrower loop have lower energy losses.
Magnetic induction measures the amount of magnetic flux passing through a unit area. Magnetic flux density is a key parameter in designing magnetic systems.
A magnetic line of force, also known as a magnetic field line, is the path showing how magnetic poles would move within the field. lines form closed loops for most magnets.
A magnetic path refers to the route taken by magnetic flux in a magnetic circuit or system. minimizes magnetic losses.
A key parameter in the design of magnetic circuits. Materials with high permeability are more effective at concentrating magnetic fields.
Magnetic poles are regions where the magnetic field is strongest. Pole polarity determines attraction and repulsion forces between magnets.
Magnetic saturation describes the maximum magnetic field intensity a material can achieve. This parameter is vital when selecting materials for high-field applications.
Magnetization refers to the process of aligning or inducing a magnetic field within a material. It can be achieved by exposure to a magnetic field, electric current flow, or contact with other magnets.
It can be achieved using a magnetic field or electric current. Control over the magnetization process enables achieving optimal parameters.
A magnetization curve, also called a B-H curve or demagnetization curve, represents the relationship between magnetic field strength (H) and magnetic induction (B). useful for selecting materials for specific applications.
Magnetized refers to the result of aligning magnetic moments in a specific direction. Magnetized materials exhibit magnetic properties and can attract or repel other magnetic materials.
Magnetomotive force (mmf) is a measure of the ability to generate a magnetic field in a magnetic circuit. Analogous to electromotive force (EMF) in electrical circuits.
In magnetism, material refers to classified as ferromagnetic, paramagnetic, or diamagnetic. Ferromagnetic materials like iron can be permanently magnetized.
Maximum energy product, denoted as BHmax, is a measure of the maximum energy a magnet can deliver per unit volume.
The formula for BHmax is:
BHmax = B × H
Where:
B: Magnetic flux density (Tesla)
H: Magnetic field strength (A/m)
For example, a magnet with B = 1 T and H = 600 kA/m achieves a BHmax of 600 kJ/m³.
High BHmax values are characteristic of neodymium magnets, making them indispensable for advanced industrial applications.
The formula for BHmax is:
BHmax = B × H
Where:
B: Magnetic flux density (Tesla)
H: Magnetic field strength (A/m)
For example, a magnet with B = 1 T and H = 600 kA/m achieves a BHmax of 600 kJ/m³.
High BHmax values are characteristic of neodymium magnets, making them indispensable for advanced industrial applications.
Maximum operating temperature (Tmax) is a crucial parameter for applications in high-temperature environments. Temperatures exceeding Tmax may result in material demagnetization.
Maxwell is represents the amount of magnetic flux passing through a surface area of one square centimeter in a magnetic field of one gauss. critical for historical and scientific magnetic applications.
Mega Gauss Oersteds (MGOe) is a unit used to express the amount of magnetic energy stored in a magnet per unit volume. This unit helps assess the magnetic potential of magnets in complex magnetic circuits.
A monopole refers to a hypothetical single magnetic pole existing independently as either a north or south magnetic pole. So far, monopoles have not been observed in nature.
Litera: N
N rating refers to a numerical designation, e.g., N35, N42, or N52, indicating the maximum energy product (BHmax). These ratings assist users in selecting appropriate magnets for specific applications.
The north pole is the pole that, when freely suspended, points toward the Earth's geographic North Pole. associated with the direction of outgoing magnetic field lines.
Litera: O
Oersted is named after Hans Christian Oersted, who discovered the relationship between electric currents and magnetic fields. 1 oersted corresponds to the field that exerts a force of one dyne on a unit magnetic pole at a distance of one centimeter.
An open circuit refers to a condition where a magnetic circuit is not closed or complete. open circuits may occur due to air gaps or insufficient magnetic materials.
Orientation refers to determines the direction and distribution of the magnetic field or flux. can significantly affect magnet interactions and circuit performance.
Litera: P
Paramagnetic materials are become magnetized in the direction of the external field due to the alignment of atomic or molecular magnetic moments. The magnetism of these materials vanishes when the external field is removed, distinguishing them from ferromagnetic materials.
Paramagnetism is a property of materials weakly attracted to magnetic fields. The magnetism disappears once the external field is removed, due to the presence of unpaired electrons.
A permanent magnet is a material or object that retains its magnetic properties indefinitely. It is made from materials with strong magnetic properties, such as iron, nickel, or cobalt alloys.
They are made from materials with high magnetic retention. Their durability and stability make them indispensable in many industrial applications.
Magnetic permeability is a property of a material determining its ability to conduct magnetic flux. High permeability enables efficient transmission of magnetic flux, critical for designing magnetic circuits.
Permeance, denoted by the symbol P, describes the ease with which magnetic flux can flow through a specific magnetic circuit.
The mathematical formula for permeance is expressed as:
P = (μ × A) / l
Where:
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
l: Length of the magnetic path (m)
For a material with μ = 4π × 10⁻⁷ H/m, A = 0.01 m², and l = 0.1 m, permeance is 1.26 × 10⁻⁵ H.
High permeability is crucial for enhancing the efficiency of magnetic systems.
The mathematical formula for permeance is expressed as:
P = (μ × A) / l
Where:
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
l: Length of the magnetic path (m)
For a material with μ = 4π × 10⁻⁷ H/m, A = 0.01 m², and l = 0.1 m, permeance is 1.26 × 10⁻⁵ H.
High permeability is crucial for enhancing the efficiency of magnetic systems.
indicates the slope of the operating line on the demagnetization curve. This coefficient impacts magnetic stability and parameters such as the energy product (BHmax) in magnetic circuits.
Plating or coating refers to the process of applying a protective layer to the surface of neodymium magnets. Thanks to coatings, magnets can be used in harsh environmental conditions.
like poles repel each other, while opposite poles attract. Understanding the polarity of magnets is crucial for their proper application and alignment in various magnetic systems.
A magnetic pole refers to one of the two ends of a magnet where the magnetic field is strongest: north or south. Their location and properties are critical for optimizing performance in magnetic applications.
Pull force, sometimes referred to as gripping force, describes a magnet's ability to maintain attachment. It can be estimated using the formula:
F = B² × A / (2 × μ₀), where:
F - Pull force (in newtons, N).
B - Magnetic flux density at the magnet's surface (in teslas, T).
A - Contact area of the magnet with the material (in m²).
μ₀ - Permeability of free space (4π × 10⁻⁷ H/m).
Example: In the case where the magnetic flux density is 1.2 T, and the magnet's contact area is 0.005 m², the pull force is:
F = (1.2)² × 0.005 / (2 × 4π × 10⁻⁷) ≈ 572 N.
F = B² × A / (2 × μ₀), where:
F - Pull force (in newtons, N).
B - Magnetic flux density at the magnet's surface (in teslas, T).
A - Contact area of the magnet with the material (in m²).
μ₀ - Permeability of free space (4π × 10⁻⁷ H/m).
Example: In the case where the magnetic flux density is 1.2 T, and the magnet's contact area is 0.005 m², the pull force is:
F = (1.2)² × 0.005 / (2 × 4π × 10⁻⁷) ≈ 572 N.
Litera: R
these magnets are known for their exceptional magnetic properties and wide applications. Due to their high magnetic strength, they are used in industries, electronics, and consumer technologies.
They are made from rare earth elements like neodymium, dysprosium, and praseodymium. These magnets are used in industries, medicine, and electronics where strong magnetic fields are required.
indicates a material's ability to concentrate magnetic flux. is a crucial parameter in magnetic engineering.
Reluctance is a measure of the opposition a magnetic circuit presents to the flow of magnetic flux. The design and geometry of the magnet and surrounding materials affect reluctance and the efficiency of magnetic circuits.
Reluctance, denoted by the symbol R, measures a magnetic circuit's opposition to magnetic flux.
The mathematical formula for reluctance is:
R = l / (μ × A)
Where:
R: Magnetic resistance (1/H)
l: Length of the magnetic path (m)
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
The larger the magnetic cross-section or permeability, the lower the magnetic resistance.
Reluctance is analogous to electrical resistance in DC circuits, making it a key parameter in designing magnetic circuits.
The mathematical formula for reluctance is:
R = l / (μ × A)
Where:
R: Magnetic resistance (1/H)
l: Length of the magnetic path (m)
μ: Magnetic permeability of the material (H/m)
A: Cross-sectional area of the magnetic path (m²)
The larger the magnetic cross-section or permeability, the lower the magnetic resistance.
Reluctance is analogous to electrical resistance in DC circuits, making it a key parameter in designing magnetic circuits.
Residual magnetism indicates the magnet's ability to retain its magnetic properties over time. Allows for assessing the long-term stability and suitability of magnets for various applications.
This occurs due to opposing magnetic fields generated by the magnets, causing them to repel each other. Is important in designing systems where avoiding contact between magnets is necessary.
Includes the use of ferromagnetic materials or magnetic conductors to guide the magnetic field. Is a critical component in designing efficient magnetic circuits.
Litera: S
Shearing force, denoted by the symbol Fs, refers to the force required to shift a magnet along the contact surface in a direction parallel to the contact plane.
The formula for shear force is:
Fs = F × tan(θ)
Where:
F: Pull force (N)
θ: Angle of the contact surface (rad)
For example, if F = 50 N and the angle θ = 30°, the shear force is approximately 28.9 N.
This parameter plays a key role in applications such as magnetic mounts or sliding mechanisms.
The formula for shear force is:
Fs = F × tan(θ)
Where:
F: Pull force (N)
θ: Angle of the contact surface (rad)
For example, if F = 50 N and the angle θ = 30°, the shear force is approximately 28.9 N.
This parameter plays a key role in applications such as magnetic mounts or sliding mechanisms.
It is the pole that, when freely suspended, points toward the Earth's geographic South Pole. Magnetic field lines flow from the north pole to the south pole, defining interaction properties.
This process involves arranging magnets in series or parallel configurations, enhancing the magnetic field. Such arrangements enable stronger magnetic interactions and improved performance in various applications, such as magnetic separators, holders, or sensors.
Litera: T
Tesla is a unit of measurement for magnetic flux density, describing the strength and intensity of a magnetic field. In practice, tesla is used to evaluate magnet performance and design precise magnetic systems.
Isotropic magnets can be magnetized in any direction, making them versatile. Isotropic magnets are ideal for general applications due to their flexibility.
Litera: W
Named after Wilhelm Eduard Weber, a German physicist and pioneer of electromagnetic theory. Useful in analyzing magnet effectiveness in applications like generators, motors, and energy storage systems.
The weight of a neodymium magnet is a critical factor influencing its applications. It can be simply determined based on its density and volume using the formula:
m = ρ × V, where:
m - mass of the magnet (in grams or kilograms).
ρ - density of the magnet (typically 7.5 g/cm³).
V - volume of the magnet (in cm³ or m³).
Example: A magnet with a density of 7.5 g/cm³ and a volume of 10 cm³, the weight is:
m = 7.5 × 10 = 75 g.
Knowing the weight is crucial in projects where balance between mass and magnetic force is important.
m = ρ × V, where:
m - mass of the magnet (in grams or kilograms).
ρ - density of the magnet (typically 7.5 g/cm³).
V - volume of the magnet (in cm³ or m³).
Example: A magnet with a density of 7.5 g/cm³ and a volume of 10 cm³, the weight is:
m = 7.5 × 10 = 75 g.
Knowing the weight is crucial in projects where balance between mass and magnetic force is important.