What physical property requirements do pure permanent magnets need to meet?

In the electronics industry, pure permanent magnets are widely used in devices such as electric meters, generators, and telephones. In order to ensure the accuracy and reliability of the equipment, what physical property requirements (such as remanence, coercive force, etc.) do pure permanent magnets need to meet?

In the electronics industry, pure permanent magnets are widely used in devices such as electric meters, generators, and telephones. In order to ensure the accuracy and reliability of these devices, pure permanent magnets need to meet the following physical property requirements:

Remanence (Br):
Remanence refers to the surface field retained after the magnet is magnetized to technical saturation and the external magnetic field is removed. In electronic equipment, the size of the remanence directly affects the magnetic field strength and working performance of the equipment. Permanent magnets should have high remanence to ensure that the equipment can generate sufficient magnetic field strength.
For example, neodymium iron boron (NdFeB) magnets have been widely used in the electronics industry due to their high remanence characteristics.

Coercive force (Hc):
Coercive force refers to the fact that after the saturation magnetization of the magnetic material, when the external magnetic field returns to zero, its magnetic induction intensity B does not return to zero. Only when a certain magnetic field is added in the opposite direction of the original magnetization field can the magnetic induction intensity return to zero. This magnetic field is called the coercive magnetic field, also known as the coercive force.
In electronic equipment, it is necessary to select materials with large coercive force (such as aluminum nickel cobalt, etc.) as permanent magnets to ensure that the magnetism of the magnet is not easily affected by external factors (such as temperature, vibration, etc.) during the use of the equipment, and to maintain a stable magnetic field output.

Magnetic stability:
Magnetic stability refers to the ability of a magnet to maintain its magnetic properties unchanged during long-term use. For electronic equipment, magnetic stability is crucial because any slight change in the magnetic field may affect the accuracy and reliability of the equipment.
Therefore, when selecting a pure permanent magnet, it is necessary to consider its magnetic stability and select those magnets that have been rigorously tested and verified.

Temperature stability:
Temperature changes may affect the magnetism of the magnet. Therefore, when selecting a pure permanent magnet, it is necessary to consider its temperature stability to ensure that the magnetism of the magnet can remain stable within the temperature range of normal operation of the equipment.

Mechanical strength:
Permanent magnets in electronic devices may need to withstand certain mechanical stresses. Therefore, when selecting pure permanent magnets, it is necessary to consider their mechanical strength to ensure that they are not prone to breakage or damage during use.

In order to ensure the accuracy and reliability of electronic devices, pure permanent magnets need to meet physical property requirements such as remanence, coercivity, magnetic stability, temperature stability and mechanical strength. When selecting pure permanent magnets, it is necessary to comprehensively consider these factors according to specific application scenarios and requirements and select the most suitable magnet material and specifications.

Rectangular pure permanent magnet