4. Spinning magnetic ferrite
Gyromagnetic ferrite is mainly used to make various microwave components, so it is also called microwave ferrite. At present, the main widely used "spinel type and pomegranate type ferrites. Spinel type magnetic ferrite is the most widely used, commonly used magnesium ferrite CMg -- Mn, Mg -- Mn -- Al2O3, Mg -- Cr ferrite, nickel ferrite (Ni -- Mg, Ni -- Zn, Ni -- Al ferrite, etc.). In addition, there are lithium ferrite CLi - Mg, Li - Al ferrite and so on.
Garnet type gyromagnetic ferrite is composed of iron oxides containing rare earth elements, the most important of which is yttrium garnet ferrite. There are also garnet gyromagnetic ferrites with little or no rare earth elements, such as Bi - Ca - V garnet.
It can be used in very high frequency band. It is made by replacing Fe in Ba, Sr and pb ferrites with Al.
5. Moment magnetic ferrite
Generally speaking, spinel ferrites with high density, uniform grain and large crystalline anisotropy can be made into moment magnetic ferrites. Common moment magnetic ferrite has; Mn-mg, Mn-Cu, Mn-Ni, Li -- Mn, Li -- Ni ferrite ceramic materials.
When the content of Fe2O3 in Mn-Mg moment magnetic ferrite is between 40 and 50%, the proportional content of MgO and MnO allows a wide selection range. The high content of MnO makes the ferrite have a good rectangular hysteresis loop, but in excess, magnetization requires a larger current, which is unfavorable to the work of the magnetic core. When Fe2O3 content is 43% and MgO: MnO: Fe2O3 is 1:3:3, Mn-Mg ferrite moment magnetic characteristics are the best. La2O3 as the main rare earth element in the formula is helpful to improve the performance of moment magnetic ferrite.
The above is only a brief introduction to the categories and processes of magnetic ceramics. The technological characteristics of magnetic ceramics are still being studied further. Be predictable; With the development of science and technology, new magnetic ceramic materials will play a huge role in more fields.
