110MHz magnetic permeability absorbing material with high temperature resistance and good flexibility to reduce radiation noise of electronic devices

Materials with ferromagnetic properties have the following characteristics:

① Even without an external magnetic field, magnetic moments still exist in various small regions (magnetic domains) inside the material. But not magnetizedmagnetic materialIn the absence of an external magnetic field, the magnetic moment direction of each magnetic domain is arbitrarily distributed, and its vector sum is zero, so the material as a whole has no magnetism.

② Easy to magnetize. This is because under the action of an external magnetic field, the magnetic moment direction of each magnetic domain tries to rotate towards the direction of the magnetic field, resulting in a large magnetic induction intensity B. According to the formula B=μ rB0 (B0 is the magnetic induction intensity in vacuum), the relative permeability μ r of magnetic materials is very high. In fact, the μ r of magnetic materials reaches 10-10, while the μ r of non-magnetic materials is ≈ 1.

③ There is a phenomenon of magnetic saturation, where B increases with the increase of H, but after reaching a certain value Bs, it no longer increases with H. BS is the saturation magnetic induction strength of the magnetic material. The reason for the saturation phenomenon is that after H reaches a certain value, the magnetic moments of all magnetic domains turn towards the direction of the magnetic field. Due to this reason, B and H do not have a linear relationship, and therefore the magnetic permeability is not a constant, but is related to the magnetic field strength.

④ There is hysteresis phenomenon. The change in magnetic induction intensity lags behind the change in magnetic field.