Ferrite Block Magnet
In addition, during the ferrite preparation process, the sintering process conditions also have an impact on the distribution of magnetic ions. Therefore, in order to grasp the basic characteristics of ferrite materials, it is necessary to understand the crystal structure of various ferrites; the distribution of metal ions in the crystal structure; and how to change their distribution.
Ferrite Block Magnet
Regarding the source of ferromagnetism of ferrite materials, it is not formed by the direct exchange of electron spins between adjacent magnetic atoms like the magnetism of general metal magnetic materials, but the distance between two magnetic ions is relatively long, And oxygen ions are sandwiched in the middle. In fact, the exchange of electron spins that form ferromagnetism is formed due to the existence of oxygen ions. This type of exchange is called super exchange in the theory of ferromagnetism. Due to the effect of super exchange, the magnetic moments of the magnetic ions on both sides of the oxygen ion are arranged in opposite directions, and the antiferromagnetism of many metal oxides comes from this. If the magnetic moments arranged in opposite directions are not equal and there is residual magnetic moment, then this kind of magnetism is called ferrimagnetism, or ferrite magnetism.
Since there are many relative positions between oxygen ions and magnetic ions in ferrite materials, there are more or less super-exchange interactions between them. Studies have shown that when the distance between oxygen ions and metal ions is close, and the angle between magnetic ions and oxygen ions is about 180°, the superexchange effect is the strongest. The arrangement direction of magnetic ions in ferrite is mainly based on the strongest super-exchange effect. Therefore, the magnetic properties of ferrite materials are not only related to the crystal structure, but also related to the distribution of magnetic ions in the crystal structure. Changing the composition of magnetic ions or nonmagnetic ions in ferrite can change the distribution of magnetic ions in the crystal structure.
In addition, during the ferrite preparation process, the sintering process conditions also have an impact on the distribution of magnetic ions. Therefore, in order to grasp the basic characteristics of ferrite materials, it is necessary to understand the crystal structure of various ferrites; the distribution of metal ions in the crystal structure; and how to change their distribution.
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