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Surface Magnetism, Remanence, And Magnetic Flux

What Exactly is Magnetism?

The electromagnetic force in a moving electric charge causes magnetism. A magnet is surrounded by an invisible magnetic field and has two ends known as poles. The north pole is oriented toward the north magnetic field of the Earth. The south pole is oriented toward the Earth’s magnetic field to the south.

A magnet’s north pole attracts the other magnet’s south pole and repels another magnet’s north pole. When you cut a magnet, you get two new magnets, each with a north and south pole.

What Exactly Is Surface Magnetism?

A magnet’s surface magnetism includes the surface magnetic field, which refers to the magnetic induction strength at a certain location on the magnet’s surface; the unit is Gauss Gs or Tesla T (1T=10000Gs). The surface magnetic field is one of the most easily measured quantities. When the size of the magnets is fixed, people often assess and compare the magnets’ performance by measuring the surface magnetic field.

It is not suited for regular measurement of certain extremely big or very tiny magnets with unusual shapes. The following two things must be understood about the surface magnetic field:

  1. The surface magnetic field is the value measured when the Gauss meter touches a specific place on the magnet’s surface and does not reflect the magnet’s overall performance.
  2. The surface magnetic field varies with location on the magnet surface. The surrounding environment readily influences the surface magnetic field. Surface magnetic fields measured by the same magnet using Gauss meters from various manufacturers may vary. The observed surface magnetic field may vary when the same magnet is tested in various surroundings.

As seen from the preceding two points, measuring the surface magnetic field is not objective and is not a metric that can properly represent the magnet’s performance. It is not suggested as a product assessment index.

Relationship Between Surface Magnetism & Remanence

The magnetic induction strength preserved in the magnetic body when the external magnetic field is progressively lowered to zero after the magnetic body has been magnetized to a saturated condition is referred to as remanence. The remanence of a magnet is governed by its properties, and the remanence of the same magnet under specific circumstances is constant and has a single value.

The remanence of the magnet controls its surface magnetic field to some degree, but it is not the same for all magnets with the same remanence. The magnet’s form, size, and magnetization also affect the surface magnetic field.

The surface magnetic field with greater remanence is stronger for two magnets of the same shape and size. The amount of remanence for two magnets with different forms, performances, and sizes cannot be determined just by the level of the surface magnetic field.

What Does The Term Remanence Exactly Entail?

The ability of a material to retain the magnetism that has been induced into it despite the absence of an external magnetic field is referred to as remanence or residual magnetism. Both of these terms refer to the same phenomenon. The remanence of a magnet can be either very high or very low, depending on the type of magnet it is. Neodymium magnets, for instance, are known for their exceptionally high remanence. Ferrite magnets, on the other hand, have a lower remanence.

The degree to which a magnet retains its magnetism can be determined by its remanence strength. This finding indicates a value associated with the maximum remanence of the specific material; the hysteresis curve can be used to determine this value. The hysteresis curve of the material illustrates both the induced magnetic flux density and the magnetization force of the material.

The remanence will behave differently depending on whether the magnetic material is considered hard or soft. Hard magnetic materials, also known as permanent magnets, possess a high degree of magnetism even without a magnetic field because of their inherent magnetic properties. On the other hand, soft magnetic materials require a lower percentage of saturation magnetization to function properly.

How Does One Go About Measuring Magnetic Remanence?

The magnetic flux density is the metric used to measure this remanence. Similarly, in accordance with the international system, it is denoted by gauss or tesla.

10.000Gauss = 1 Tesla.

Different Kinds Of Remanence

There are a few distinct categories of remanence, including:

Saturation remanence: the sort of residual magnetism with the greatest amount of saturation remanence is called saturation remanence.

Isothermal residual magnetism is a technique that enables us to determine the residual magnetism of very tiny particles. This technique may be categorized as follows:

DC demagnetization remagnetization: The magnet becomes magnetized in one direction by applying an electric current until the saturation point is achieved. This process is known as direct current (DC) demagnetization and remagnetization.

AC demagnetization and remagnetization: A current outside the magnet causes it to become magnetized again.

Reduction of residual magnetism: At this point in the process, the remanence has been reduced due to going through the magnetization and demagnetization steps.

Is It Possible To Lose Remanence?

A magnet is said to have demagnetized when the remanence value has decreased to its greatest extent and reached its maximum. That is to say. The remanence may vanish if strong vibrations are present and when there is high heat. If the temperature threshold is exceeded, there is a possibility that the magnet will lose its remanence. Depending on the elevated temperature subjected to the material, this loss may be either reversible, irreversible, or even permanent.

Magnetic Flux

What Exactly Does Magnetic Flux Mean?

A region’s magnetic flux can be considered a measurement of the total magnetic field as it moves through that region. It is a helpful instrument that may assist in describing the magnetic field’s impact on anything occupying a certain space. The measurement of magnetic flux is dependent on the specific location that is being investigated. We have complete control over the size and orientation of the region to the magnetic field, so we can create it in whatever size we choose.

Magnetic flux is the number of magnetic field lines moving through an area completely enclosed. This value determines the overall magnetic field strength that traverses a given surface area by computing this value.

The area under examination may be of any size, and it could face several different directions relative to the direction of the magnetic field. It is common to practice to denote magnetic flux with the Greek letter phi or the suffix B derived from phi. The magnetic flux may be denoted by the sign or B.

You need to comprehensively understand the material if you want to grasp the difficult concept of magnetic flux. Magnetic field lines and magnetic flux are called “lines of force.” The fundamental characteristic of magnetism is comprised of two areas known as magnetic poles, which are present in all magnets. Each of these magnetic poles exists in a pair at all times. In addition, they create invisible chains, also referred to as vector fields, all around the circuit in a pattern referred to as flux. The term “magnetic flux” refers to the number of magnetic field lines that go through a certain region, such as the space contained by a wire loop.

Gaining A Better Understanding of Magnetic Flux

As was said before, magnets of any form and size create invisible chains of magnetic field lines that begin at the North Pole and finish at the South Pole. These chains begin at the North Pole and conclude at the South Pole. These poles are surrounded by a magnetic field, which results in the formation of lines of force. In most cases, it is impossible to perceive the magnetic flux lines with the human eye, but this phenomenon may be seen using iron fillings. Near the poles, you’ll find that the magnetic flux lines are more concentrated and robust. The sign for magnetic flux is “Phi,” and it looks like this: Remember that the magnetic flux of a closed space is always zero; this is an important fact to keep in mind.

Important Facts About Magnetic Flux

Remembering these key points relating to “magnetic flux” is essential to avoid confusion about this topic. To begin, separate lines of force are never allowed to intersect. Second, the flow of magnetic flux remains unbroken at all times. Third, the lines of force go from north to south as they traverse the landscape. Fourth, the magnetic flux is strongest close to the ends and decreases as it moves away from those points. Fifth, as they go from north to south, they will always wrap themselves in a tight circle around the magnet. Sixth, there is no magnetic flux in a closed region such as a ball since it is impossible for there to be. Seventh, the magnetic flux of an opened region (disk surface, square surface) need not be zero for a flux there.


Thanks for reading our article up to this point; we hope it helped you better comprehend surface magnetism, remanence, and magnetic flux. If you are interested in more information about magnets, we recommend you visit our pages for more enlightening information.


Article by

ROBO Magnetic Product Team

We are the manufacturer with 16 years of experience in custom neodymium magnets.

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