CN-122010548-A - BaM ferrite material based on samarium and copper co-substitution and preparation method thereof

Abstract

The invention discloses a BaM ferrite material based on samarium and copper co-substitution and a preparation method thereof, and belongs to the technical field of ferrite materials, wherein the molecular formula of the ferrite material is Ba 1‑ x Sm x Fe 12‑x Cu x O 19, , wherein 0< x is less than or equal to 0.25, the preparation method of combining a wet solid phase reaction method and magnetic field orientation is adopted, the preparation method comprises the specific steps of proportioning according to a reaction mode, carrying out primary ball milling, drying, sieving, presintering, adding 8wt% of polynaphthalenesulfonic acid sodium dispersant, carrying out secondary ball milling, orientation and sintering, the magnetic properties of ferrite are regulated by adding substituents with different amounts, the remanence ratio of all materials is larger than 0.5, the remanence ratio of all materials is shown to have single domain or quasi-single domain state, and in addition, when the substitution amount x=0.10, the remanence ratio of the material is up to 0.83. The ferromagnetic resonance line width measurement of high frequency is carried out, and the ferromagnetic resonance line width measurement shows that the ferromagnetic resonance line width measurement has a low line width of 800Oe in a 55GHz frequency band.

Inventors

• LIU QIAN
• Chen Houjiao
• WU YUXIN
• LI CHANG
• TAN XIAO
• LIAO YONGJIE
• LI ZIYANG

Assignees

• 成都理工大学

Dates

Publication Date

20260512

Application Date

20260304

Claims (9)

1. 1. A BaM ferrite material based on samarium and copper co-substitution is characterized in that the molecular formula of the ferrite material is Ba 1-x Sm x Fe 12-x Cu x O 19, , wherein x is 0< x and less than or equal to 0.25.
2. 2. The BaM ferrite material based on samarium, copper co-substitution of claim 1, wherein x = 0.1.
3. 3. The preparation method of the BaM ferrite material based on samarium and copper co-substitution as claimed in claim 1 or 2, which is characterized by comprising the following steps: S1, burdening, namely selecting BaCO 3 、Sm 2 O 3 、Fe 2 O 3 and CuO as raw materials, calculating according to a molecular formula Ba 1-x Sm x Fe 12-x Cu x O 19 , and accurately weighing the burdening; S2, performing primary ball milling, namely mixing the ingredients weighed in the step S1 with deionized water, performing primary ball milling, and obtaining primary ball milling slurry after the ball milling is completed; s3, presintering, namely drying and sieving the slurry obtained in the step S2 after primary ball milling, placing the slurry in a high-temperature box-type furnace, heating and preserving heat in an air atmosphere, and cooling the slurry to room temperature along with the furnace to obtain presintering powder; S4, adding a sintering aid, namely weighing the presintered powder obtained in the step S3, and adding 8wt% of polynaphthalenesulfonic acid sodium dispersant for mixing and proportioning; S5, secondary ball milling, namely mixing the weighed ingredients in the step S4 with quantitative deionized water, and performing secondary ball milling to obtain secondary ball milling slurry after ball milling is completed; S6, performing orientation pressing on the green body, namely pouring the slurry obtained in the step S5 into a mould, pressing the slurry into a cylindrical green body by pressurizing force, and applying a magnetic field parallel to the pressurizing force at the same time to magnetize the single-domain particles and directionally arranging the single-domain particles in the direction of an external magnetic field; s7, sintering, namely placing the cylindrical green body obtained in the step S6 into a high-temperature box-type furnace for sintering, heating and preserving heat in an air atmosphere, and cooling to room temperature along with the furnace.
4. 4. The method of claim 3, wherein in the step S2, the mass of the added deionized water is 150% -250% of that of the raw material, and the ball milling is performed for 12 hours at a rotating speed of 300 r/min.
5. 5. The method according to claim 3, wherein in the step S3, the temperature is raised to 1200 ℃ at a rate of 2-5 ℃ per minute, and the holding time is 4 hours.
6. 6. The method of claim 3, wherein the dispersant is 8-10% by weight of the pre-sintered powder in the step S4.
7. 7. The method of claim 3, wherein in step S5, the mass of the deionized water added is 150% -250% of that of the raw material, and the secondary ball milling is performed at a rotational speed of 500r/min for 24 hours.
8. 8. The method according to claim 3, wherein in step S6, the magnetic field strength at the time of pressing is 10kOe and the molding pressure is 4MPa.
9. 9. The method according to claim 3, wherein in step S7, the temperature is raised to 1000 ℃ at a rate of 2-5 ℃ per minute, and the holding time is 4 hours.

Description

BaM ferrite material based on samarium and copper co-substitution and preparation method thereof Technical Field The invention relates to the technical field of ferrite materials, in particular to a BaM ferrite material based on samarium and copper substitution and a preparation method thereof. Background With the continuous evolution of the fifth generation mobile communication technology, the low-orbit satellite internet and the automatic driving vehicle-mounted radar system to the millimeter wave frequency band, the radio frequency front end provides more severe requirements on the high-frequency performance and the integration level of core nonreciprocal devices such as a circulator and the like. The traditional circulator based on garnet or spinel ferrite has low magnetocrystalline anisotropy field, and the circulator must rely on an external permanent magnet with huge volume in millimeter wave frequency band to provide necessary bias magnetic field, which becomes a fundamental obstacle for realizing miniaturization, low power consumption and high reliability of the system. Under the background, the M-shaped hexaferrite (such as BaFe 12O19、SrFe12O19) shows unique self-bias characteristic by virtue of the strong uniaxial magnetocrystalline anisotropy field of which the temperature is up to 1.7T, and provides an ideal material platform for realizing the millimeter wave circulator without permanent magnets and with high temperature stability. However, the inherent high anisotropy field, while imparting high frequency self-biasing capability, also results in ferromagnetic resonant frequencies that are too high to effectively cover and optimize performance in critical millimeter wave windows such as Ka-band (26.5-40 GHz) and U-band (40-60 GHz). In order to solve the problem of high-frequency suitability, fe 3+ is selectively doped by Co 2+-Ti4+、Zn2+-Zr4+ plasma, so that the method becomes a core technical means for accurately regulating and controlling the high-frequency magnetic performance of the material, the magnetic crystal anisotropy field can be finely regulated on the premise of not obviously sacrificing the saturation magnetization, so that the ferromagnetic resonance frequency of the material is customized in a specific millimeter wave frequency band, meanwhile, the doping effectively optimizes the gyromagnetic performance and the residual magnetic ratio of the material, and is directly related to the reduction of the insertion loss of a millimeter wave circulator and the improvement of isolation. Therefore, the M-type hexaferrite is subjected to ion doping, and the far-reaching significance is that the high-performance material is converted from a candidate with fixed characteristics into an engineering material with designable and optimizable performance in a millimeter wave frequency band, so that a key material solution is provided for overcoming the technical bottleneck of the future millimeter wave integrated radio frequency front end. Disclosure of Invention One of the purposes of the present invention is to provide a BaM ferrite material based on samarium and copper substitution together, so as to solve the above problems. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: A BaM ferrite material based on samarium and copper substitution is provided, wherein the molecular formula of the ferrite material is Ba 1-xSmxFe12-xCuxO19, and x is more than 0 and less than or equal to 0.25. Compared with the Chinese patent application CN109206131A which adopts doped Sm 3+ and Cu 2+ to jointly replace Sr 2+ and Fe 3+ in strontium ferrite, the invention adopts a barium ferrite matrix: First, the barium ion (Ba 2+) has a larger ionic radius and its lattice site provides a more relaxed and compatible crystalline environment for substitution of the larger-sized trivalent rare earth ion samarium (Sm 3+). The substitution can more effectively introduce lattice distortion and enhance magnetocrystalline anisotropy, thereby providing a structural foundation for the key permanent magnet performance of improving coercive force and avoiding the problem of phase instability caused by overlarge lattice mismatch. Secondly, the substitution of copper ions (Cu 2+) on iron sites (Fe 3+) aims at optimizing intrinsic magnetism through the regulation and control of valence states and magnetic moments. The crystal field environment of the barium ferrite matrix has subtle difference with that of the strontium ferrite, and the interaction of the barium ferrite matrix and copper ions is more beneficial to promoting densification and grain refinement in the sintering process, and meanwhile, the abnormal growth of grains is effectively restrained. This creates an advantage for the uniform fine-grain microstructure necessary to achieve high coercivity. The invention selects barium ferrite as a matrix based on the deep synergistic effect of the barium ferrite and the specific dopin