High-stability garnet microwave ferrite magnetic sheet and preparation method thereof

Abstract

The invention belongs to the technical field of magnetic materials, and discloses a high-stability garnet microwave ferrite magnetic sheet and a preparation method thereof. The material composition ofthe high-stability garnet microwave ferrite magnetic sheet is Y<3-f-2d-a>Gd<f>Ca<2d+a>Bi<e>Fe<5-a-b-c-d-sigma>SnInMn<c>V<d>O<12>, wherein a is more than 0 and no more than 0.7; b is more than 0and no more than 0.7; c is more than 0 and no more than 0.6; d is more than 0 and no more than 1.5; e is more than 0 and no more than 0.6; f is more than 0 and no more than 0.8; and sigma is more than 0 and no more than 0.4. According to the high-stability garnet microwave ferrite magnetic sheet, Bi<3+> ions are added into the material, so the dielectric constant of the material is improved, anda Curie temperature is increased; and in addition, SnO<2>, In<2>O<3>, SnO<2> and In<2>O<3> are added into the material, so the anisotropy coefficient K of the material can be reduced, and the ferromagnetic resonance linewidth Delta(H) of the material is reduced. In terms of the process, high-pressure sintering is adopted to replace normal-pressure sintering, so sintering density is improved, the porosity of the material is reduced, and the ferromagnetic resonance linewidth Delta(H) of the material is reduced. Thus, the problem that the temperature coefficient of the material is poor is solved,and the material is guaranteed to have low ferromagnetic resonance linewidth Delta(H), high dielectric constant and high Curie temperature.

Description

technical field [0001] The invention relates to the technical field of magnetic materials, in particular to a high-stability garnet microwave ferrite magnetic sheet and a preparation method thereof. Background technique [0002] 5G mobile communication uses a higher frequency band and faster data transmission rate, which also puts forward higher requirements on the performance of microwave ferrite materials used in circulators and isolators in communication base stations: 1) Ferromagnetic resonance linewidth (△H ) Narrow; 2) High Curie temperature (TC); 3) High dielectric constant (ε'); 4) Low dielectric loss (tanδ); 5) Excellent temperature stability. [0003] In the production of microwave ferrite circulators / isolators for 5G communications, it often appears that the device has excellent test performance at room temperature, but it is prone to unqualified performance when tested at high and low temperatures (-40 ° C ~ +85 ° C), resulting in The main reason for this phenom...

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Problems solved by technology

[0003] In the production of microwave ferrite circulators / isolators for 5G communications, it often appears that the device has excellent test performance at room temperature, but it is prone to unqualified performance when tested at high and low temperatures (-40 ° C ~ +85 ° C), resulting in The main reason for this phenomenon is that the temperature coefficient of the microwave ferrite magnetic sheet material is poor, and the saturation magnetization is easy to change significantly with the change of temperature, so the performance of the device changes with the change of temperature.

The general solution to this problem is to add rare earth ions Gd 3+ , Gd 3+ It has the effect of improving the temperature coefficient of the material, but at the same time it will also cause problems such as the increase of the ferromagnetic resonance line width △H, the decrease of the Curie temperature, and the decrease of the dielectric constant.

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