Neodymium magnet is a kind of high-performance permanent magnetic material, which is composed of neodymium, iron, boron and other elements. It has very strong magnetism and is currently one of the most powerful permanent magnet materials used commercially. Neodymium magnet has a very high magnetic field strength and excellent magnetic force and magnetic energy product. Therefore, it is widely used in many fields, including electronic technology, electric motors, sensors, magnets, etc.The magnetism of Neodymium magnet comes from its lattice structure and atomic alignment. The lattice structure of Neodymium magnet is highly ordered and belongs to Tetragonal crystal system. Atoms are arranged in a regular manner in the lattice, and their magnetic moments remain consistent, with strong interactions between them. This ordered arrangement and interaction make Neodymium magnet have strong magnetic properties.The magnetism of Neodymium magnet can be adjusted and improved by different preparation processes and processing methods. For example, China neodymium magnets can be made into magnets with complex shapes through powder metallurgy process. In addition, measures such as heat treatment, magnetization treatment, and coating can also be taken to further enhance its magnetic properties and stability.However, it should be noted that the magnetic properties of Neodymium magnet will be reduced at high temperatures. The critical magnetic temperature of Neodymium magnet is generally between 200-300 ℃. When the temperature range is exceeded, the magnetization and magnetic force of Neodymium magnet will gradually weaken, or even completely lose its magnetism. Therefore, in practical applications, it is necessary to select the appropriate operating temperature according to the critical magnetic temperature of Neodymium magnet materials.

Ⅰ.The magnetic properties of Neodymium magnet and the principle of temperature change

A. Basic magnetic properties of Neodymium magnet: Neodymium magnet is a kind of rare earth permanent magnetic material with very strong magnetic properties. It has the characteristics of high magnetic energy product, high remanence and high Coercivity. The magnetic field strength of Neodymium magnet is usually higher than that of ferrite and aluminum nickel cobalt magnets. This makes Neodymium magnet widely used in many applications, such as motors, sensors and magnets.

B. Relationship between atomic alignment and magnetic moment: the magnetism of Neodymium magnet is realized by the interaction of atomic magnetic moment. The atomic magnetic moment is composed of the spin of electrons and the orbital magnetic moment. When these atoms are arranged in the lattice, their magnetic moment interaction leads to the generation of magnetism. In the Neodymium magnet, the magnetic moment of the atom mainly comes from seven unpaired neodymium ions, whose spins are in the same direction as the orbital magnetic moment. In this way, a strong magnetic field is generated, resulting in the strong magnetism of Neodymium magnet.

C. The effect of temperature changes on atomic alignment: The arrangement and interaction of atoms in the lattice are determined by temperature. With the increase of temperature, the Thermal motion of atoms increases, and the interaction between atoms is relatively weakened, which leads to the instability of the orderly arrangement of atoms. This will affect the atomic alignment of the Neodymium magnet, thus affecting its magnetic properties. At high temperatures, the Thermal motion of atoms is more intense, and the interaction between atoms is weakened, leading to the weakening of the magnetization and magnetic force of Neodymium magnet.

D. Critical magnetic temperature of Neodymium magnet: The critical magnetic temperature of Neodymium magnet refers to the temperature at which Neodymium magnet loses its magnetism at high temperature. Generally speaking, the critical magnetic temperature of Neodymium magnet is about 200-300 ℃. When the temperature exceeds the critical magnetic temperature, the atomic alignment of the Neodymium magnet is destroyed, and the magnetic moment direction is randomly distributed, resulting in the weakening or even complete loss of magnetization and magnetic force. Therefore, in application, attention should be paid to controlling the working temperature of Neodymium magnet to maintain its stable magnetic properties.

Ⅱ.Influence of temperature on the magnetism of Neodymium magnet

A. Influence of temperature change on the magnetization of Neodymium magnet: temperature change will affect the magnetization of Neodymium magnet. Generally speaking, with the increase of temperature, the magnetization of Neodymium magnet will decrease and the magnetization curve will become flat. This is because the high temperature will cause the magnetic domain in the Neodymium magnet to become more irregular, resulting in a decrease in the magnetization of the small neodymium disc magnet.

B. Influence of temperature change on Coercivity of Neodymium magnet: Coercivity refers to that the applied magnetic field strength reaches the critical value of complete magnetization of the magnet during magnetization. The change of temperature will affect the Coercivity of Neodymium magnet. Generally, at high temperature, the Coercivity of Neodymium magnet will decrease, while at low temperature, the Coercivity will increase. This is because high temperatures can increase the thermal excitation of magnetic domains, requiring a smaller magnetic field to magnetize the entire magnet.

C. Influence of temperature change on moment damping and remanence of Neodymium magnet: moment damping refers to the degree of attenuation of magnetic moment during magnetization of magnet, and remanence refers to the degree of magnetization that Neodymium magnet still has under the effect of demagnetization. The change of temperature will affect the moment damping and remanence of Neodymium magnet. Generally speaking, an increase in temperature will lead to an increase in the moment damping of neodymium magnets, making the magnetization process more rapid. At the same time, the rise of temperature will also reduce the remanence of Neodymium magnet, making it easier to lose magnetization under the action of demagnetization.

Ⅲ.Application and control of Neodymium magnet magnetic loss

A. Temperature limit for use of Neodymium magnet: the magnetic properties of Neodymium magnet will be affected by high temperature, so it is necessary to limit the working temperature of Neodymium magnet in practical applications. Generally speaking, the working temperature of Neodymium magnet should be lower than its magnetic critical temperature to ensure the stability of magnetic performance. The specific operating temperature limit will vary according to different applications and specific materials. It is generally recommended to use Neodymium magnet below 100-150 ℃.

B. The consideration of temperature on magnetic force in magnet design: When designing magnets, the influence of temperature on magnetic force is an important factor to consider. High temperature will reduce the magnetic force of Neodymium magnet, so it is necessary to consider the influence of working temperature in the design process. A common method is to choose magnet materials with good temperature stability, or take cooling measures to reduce the working temperature of the magnet to ensure that it can maintain sufficient magnetic force in high-temperature environments.

C. Methods to improve the temperature stability of Neodymium magnet: In order to improve the temperature stability of Neodymium magnet at high temperatures, the following methods can be adopted:Adding alloy elements: adding alloy elements such as aluminum and nickel to Neodymium magnet can improve its high-temperature resistance.Surface coating treatment: special treatment on the surface of Neodymium magnet, such as electroplating or coating a layer of protective material, can improve its high-temperature resistance.Magnet design optimization: by optimizing the structure and geometry of the magnet, the temperature rise and heat loss of Neodymium magnet at high temperatures can be reduced, thus improving the temperature stability.Cooling measures:proper cooling measures, such as cooling liquid or fan cooling, can effectively reduce the working temperature of Neodymium magnet and improve its temperature stability.It should be noted that although the temperature stability of the Neodymium magnet can be improved by the above methods, the magnetism of the Neodymium magnet may be lost in extreme high temperature environments if its magnetic critical temperature is exceeded. Therefore, in high-temperature applications, other alternative materials or measures need to be considered to meet the demand.

In conclusion

The temperature stability of Neodymium magnet is crucial to maintain its magnetic properties and application effects. When designing and selecting Neodymium magnet, it is necessary to consider its magnetization characteristics in a specific temperature range and take corresponding measures to keep its performance stable. This can include selecting appropriate materials, using packaging or heat dissipation designs to reduce temperature effects, and controlling environmental conditions for temperature changes.Our company is a China neodymium disc magnets factory,（Especially for the production of magnets of different shapes, it has its own experience）if you need this products,please contact us without hesitate.