NiCuZn gyromagnetic ferrite material and preparation method thereof

Abstract

The invention discloses a NiCuZn gyromagnetic ferrite material and a preparation method thereof, and belongs to the technical field of ferrite materials, the molecular formula of the material is Ni < 0.26 > Cu < 0.22 > Zn < 0.52 > Zr < x > Fe < 2-4x / 3O4, the invention discloses a NiCuZn ferrite and a preparation method thereof.The NiCuZn ferrite is prepared from NiCuZn ferrite, x is smaller than or equal to 0.03, the preparation method comprises the steps of burdening, primary ball milling, pre-sintering, secondary ball milling, granulation forming, sintering and the like, the NiCuZn ferrite has good magnetic performance, meanwhile, in order to meet the requirements for miniaturization and integration of LTCC, the sintering temperature is effectively lowered to 950 DEG C or below, good rotary magnetic performance is kept, and the preparation method is suitable for industrial production. Comprising relatively low ferromagnetic resonance line width, relatively low coercive force and relatively high saturation magnetization intensity.

Description

Technical Field

[0001] The invention relates to the technical field of ferrite materials, and in particular to a NiCuZn gyromagnetic ferrite material and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of the electronic information industry, electronic equipment is evolving towards miniaturization, high frequency, integration and diversification. In this context, low temperature co-fired ceramic (LTCC) technology has received widespread attention and attention due to its significant advantages in improving device integration and reducing production costs. The key to LTCC technology is that the materials used must be co-fired with silver (Ag) electrodes, which requires that the sintering temperature must be lower than 961 °C. Therefore, reducing the sintering temperature while ensuring material performance has become a challenging technical problem.

[0003] Microwave ferrite devices are indispensable key components in electronic communication equipment and systems, and their gyromagnetic properties are one of the main indicators for evaluating the functions and performance of microwave ferrite devices. Among many ferrite materials, NiCuZn ferrite has broad application prospects in the field of microwave devices due to its high saturation magnetization, low coercivity and low ferromagnetic resonance linewidth. However, the current research on the gyromagnetic properties of low-temperature sintered NiCuZn ferrite is still insufficient, lacking systematic and in-depth exploration.

[0004] Therefore, developing a NiCuZn ferrite that can be sintered at low temperatures not only meets the strict requirements of the LTCC process, but also must have excellent gyromagnetic properties, which has become a major technical challenge that needs to be solved urgently. This research direction will not only help promote the application and development of microwave ferrites, but also is expected to promote technological progress in the entire electronic information industry and meet the growing demand for diversified products. Summary of the invention

[0005] One of the objectives of the present invention is to provide a NiCuZn gyromagnetic ferrite material that meets the requirements of the LTCC process and has excellent gyromagnetic properties, so as to solve the above problems.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: a NiCuZn gyromagnetic ferrite material, the molecular formula of which is Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, of which 0.00 <x ≤ 0.03。

[0007] As a preferred technical solution, x=0.03.

[0008] The second object of the present invention is to provide a method for preparing the above-mentioned NiCuZn spinel ferrite material, comprising the following steps: (1) Weighing materials: According to the molecular formula Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where 0.00 < x ≤ 0.03, weigh Fe2O3, NiO, CuO, ZnO as main materials, and ZrO2 as an ion substitute; (2) Primary ball milling: Ball mill the powders weighed in step (1), dry them after ball milling, and screen them; (3) Pre-sintering: Put the powders obtained by screening in step (2) into a sintering furnace for pre-sintering, and then naturally cool them to room temperature to obtain the NiCuZn main material; (4) Secondary ball milling: Weigh the NiCuZn main material obtained in step (3), denoted as m 01 , and then weigh Bi2O3, denoted as m 11 ; Then mix the weighed m 01 and m 11 to form NiCuZn powders for secondary ball milling; (5) Molding: Then take out the NiCuZn powder after secondary ball milling and dry it, add polyvinyl alcohol, granulate and press it into a green body; (6) Sintering: Then put the green body into a sintering furnace for sintering to obtain the NiCuZn spinel ferrite material.

[0009] In the present invention, ZrO2 is used as an ion substitute and is mixed and ball milled with the main materials before pre-sintering, which can achieve better substitution. The present invention adopts ion substitution and a sintering aid to effectively reduce the sintering temperature of the ferrite material and improve the densification degree, microstructure and gyromagnetic properties.

[0010] As a preferred technical solution, in step (2), the mass ratio of the powder, water and iron balls is approximately 1:1.5:3, the ball milling time is 4 - 8 h; dry it at 80 - 120 °C after ball milling; screen it with an 80 - 120 mesh sieve after drying.

[0011] As a preferred technical solution, in step (3), the process parameters of the pre-sintering are: heating up to 700 - 900 °C at a rate of 2 - 5 °C / min and holding for 2 - 4 h, and then cooling down to 500 - 600 °C at a rate of 2 - 5 °C / min.

[0012] As a preferred technical solution, in step (4), m 11 = m 01´1 wt.%, the mass ratio of NiCuZn powder, water and iron ball is about 1:1.5:3, the ball milling time is 4~8 h, and the ball milling speed is 250~300 r / min.

[0013] As a preferred technical solution, in step (5), the pressure is 10-20 MPa, and the pressure is maintained for 20-40 s.

[0014] As a preferred technical solution, in step (6), the sintering process parameters are: first increase the temperature to 500-600 °C at a heating rate of 2-5 °C / min and keep it at that temperature for 1-2 h, then increase the temperature to 900-920 °C at a heating rate of 2-5 °C / min and sinter for 2-4 h, then cool down to 500-600 °C at a heating rate of 2-5 °C / min and cool down naturally to room temperature along with the furnace.

[0015] Compared with the prior art, the NiCuZn ferrite of the present invention has many significant advantages: First of all, the material has excellent gyromagnetic properties and can effectively meet the performance requirements in high-frequency microwave applications. In order to further adapt to the strict requirements of miniaturization and integration in the low-temperature co-fired ceramic (LTCC) process, the present invention uses Bi2O3 as a sintering aid to successfully reduce the sintering temperature to below 950 °C. In addition, by adding ZrO2 as an ion substitute, NiCuZn ferrite with excellent gyromagnetic properties is successfully prepared under low temperature conditions. The introduction of ZrO2 improves the microstructure of the material, promotes the uniform growth of grains, and effectively reduces the defects and pores that may appear during the sintering process. This optimized microstructure makes NiCuZn ferrite show higher saturation magnetization, lower coercive force and lower ferromagnetic resonance linewidth in terms of gyromagnetic properties. The successful development of this technology not only provides a new preparation idea for NiCuZn ferrite materials under the LTCC process, but also lays a foundation for improving the performance of microwave devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The XRD patterns of the NiCuZn gyromagnetic ferrite materials prepared in Examples 1, 2, 3 and 4 of the present invention are as follows; Figure 2 The SEM images of the NiCuZn gyromagnetic ferrite materials prepared in Examples 1, 2, 3 and 4 of the present invention are as follows; Figure 3 (a) is the NiCuZn gyromagnetic ferrite material prepared in Examples 1, 2, 3, and 4 of the present invention M s Trend diagram, (b) is the VSM diagram of the material of Example 4; Figure 4The Δ of the NiCuZn gyromagnetic ferrite material prepared in Examples 1, 2, 3, and 4 of the present invention is H picture. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Example 1

[0018] A NiCuZn gyromagnetic ferrite material, the preparation method of which comprises: (1) Weighing: According to the molecular formula Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where x = 0.00, Fe2O3, NiO, CuO, ZnO are weighed as the main materials, and ZrO2 is used as the ion substitute; (2) Ball milling: The powder weighed in step (1) is ball milled once (wherein the mass ratio of powder, water and iron balls is about 1:1.5:3) for 4 to 8 h. After being taken out, the powder is dried at 80 to 120 °C and sieved with a sieve of 80 to 120 mesh. (3) Pre-sintering: the powder obtained by sieving in step (2) is placed in a sintering furnace, heated to 700-900°C at a rate of 2-5°C / min and kept at this temperature for 2-4 h, then cooled to 500-600°C at a rate of 2-5°C / min, and then naturally cooled to room temperature to obtain NiCuZn main material; (4) Secondary ball milling: Weigh the NiCuZn main material obtained in step (3), denoted as m 01 , and then weigh m 11 =m 01 ´1wt.% Bi2O3; then weigh the m 01 and m 11 The mixture is mixed into NiCuZn powder and then subjected to secondary ball milling. The mass ratio of NiCuZn powder, water and iron ball is about 1:1.5:3. The ball milling time is 4-8 h and the ball milling speed is 250-300 r / min. (5) Molding: The NiCuZn powder after the secondary ball milling is then taken out and dried, polyvinyl alcohol (PVA) is added to form granules and pressed into blanks. The blanks are formed by pressing the granulated NiCuZn powder into sheets using a mold at a pressure of 10-20 MPa and a pressure holding time of 20-40 s. (6) Sintering: Place the blank into a sintering furnace, first heat the temperature to 500-600 °C at a heating rate of 2-5 °C / min and keep it at that temperature for 1-2 h, then heat the temperature to 900-920 °C at a heating rate of 2-5 °C / min and sinter for 2-4 h, then cool the temperature to 500-600 °C at a heating rate of 2-5 °C / min and cool it naturally to room temperature in the furnace, thereby obtaining the NiCuZn gyromagnetic ferrite material. Example 2

[0019] A NiCuZn gyromagnetic ferrite material, the preparation method of which is basically the same as that of Example 1, except that: in step 2, according to the molecular formula Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where x=0.01, weigh the ion substitute ZrO2. Example 3

[0020] A NiCuZn gyromagnetic ferrite material, the preparation method of which is basically the same as that of Example 1, except that: in step 2, according to the molecular formula Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where x=0.02, weigh the ion substitute ZrO2. Example 4

[0021] A NiCuZn gyromagnetic ferrite material, the preparation method of which is basically the same as that of Example 1, except that: in step 2, according to the molecular formula Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where x=0.03, weigh the ion substitute ZrO2.

[0022] Characterization of the NiCuZn gyromagnetic ferrite materials prepared in Examples 1, 2, 3, and 4.

[0023] First, the X-ray diffraction pattern of the ferrite material obtained in the above embodiment is as follows: Figure 1 As shown. Figure 1It can be seen that the diffraction peaks corresponding to the (111), (220), (311), (222), (400), (422), (511), (440), (620) and (622) crystal planes match well with the spinel ferrite standard card (PDF#73-2314), confirming that all samples are formed by single-phase NiCuZn ferrite. This indicates that the addition of ZrO2 and Bi2O3 mixture does not change the phase composition of NiCuZn ferrite; Then, the SEM images of the NiCuZn gyromagnetic ferrite materials prepared in Examples 1, 2, 3, and 4 are as follows: Figure 2 As shown in the figure, it can be seen that the grains of the ferrite material in Example 4 grow significantly, Bi2O3 provides a liquid phase during the sintering process to reduce the sintering temperature, and the grains are uniform, which greatly improves the saturation magnetization of the material.

[0024] The saturation magnetization of the NiCuZn gyromagnetic ferrites prepared in Examples 1, 2, 3, and 4 was tested, and the hysteresis loop of the material prepared in Example 4 was measured using a vibrating sample magnetometer (VSM, LakeShore 7404, USA). The results are as follows: Figure 3 As shown, from Figure 3 As can be seen from (a), with the increase of ZrO2 content, the saturation magnetization ( M s ) increased from 61.56 emu / g to 62.15 emu / g and then decreased to 60.65 emu / g; wherein the saturation magnetization intensity ( M s ) is 60.65emu / g.

[0025] The gyromagnetic properties (ferromagnetic resonance line width) of the NiCuZn ferrites prepared in Examples 1, 2, 3, and 4 were tested. The results are as follows: Figure 4 As shown in the figure, it can be seen that the Δ H It is 170.69 Oe.

[0026] The present invention reduces the sintering temperature of NiCuZn ferrite to below 950°C, and finally obtains a uniform, dense NiCuZn ferrite material with excellent gyromagnetic properties at a low sintering temperature.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A NiCuZn gyromagnetic ferrite material, characterized in that: The molecular formula of the material is Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where 0.00 < x ≤ 0.

03.

2. The NiCuZn gyromagnetic ferrite material according to claim 1, characterized in that: x = 0.03。 3. The method for preparing the NiCuZn gyromagnetic ferrite material according to claim 1 or 2, characterized in that: The steps include: (1) Weighing: According to the molecular formula Ni 0.26 Cu 0.22 Zn 0.52 Zr x Fe 2-4x / 3 O4, where 0.00 < x ≤ 0.03, Fe2O3, NiO, CuO, ZnO are weighed as main materials, and ZrO2 is used as an ion substitute; (2) primary ball milling: the powder weighed in step (1) is subjected to primary ball milling, and then dried and sieved; (3) Pre-sintering: The powder obtained by sieving in step (2) is placed in a sintering furnace for pre-sintering, and then naturally cooled to room temperature to obtain NiCuZn main material; (4) Secondary ball milling: Weigh the NiCuZn main material obtained in step (3), denoted as m 01 , and then weigh Bi2O3, recorded as m 11 ; Then the measured m 01 and m 11 The mixture is prepared into NiCuZn powder and subjected to secondary ball milling; (5) Molding: The NiCuZn slurry after the secondary ball milling is then taken out and dried, polyvinyl alcohol is added, granulated and pressed into a blank; (6) Sintering: The blank is then placed in a sintering furnace for sintering to obtain the NiCuZn gyromagnetic ferrite material.

4. The preparation method according to claim 3, characterized in that: In step (2), the mass ratio of powder, water and iron balls is about 1:1.5:3, and the ball milling time is 4-8 h; after ball milling, the powder is dried at 80-120 °C; after drying, the powder is sieved with a mesh sieve of 80-120.

5. The preparation method according to claim 3, characterized in that: In step (3), the process parameters of the pre-sintering are: heating to 700-900°C at a rate of 2-5°C / min and keeping the temperature for 2-4 hours, and then cooling to 500-600°C at a rate of 2-5°C / min.

6. The preparation method according to claim 3, characterized in that: In step (4), m 11 =m 01 ´1 wt.%, the mass ratio of NiCuZn powder, water and iron ball is about 1:1.5:3, the ball milling time is 4~8 h, and the ball milling speed is 250~300 r / min.

7. The preparation method according to claim 3, characterized in that: In step (5), the pressure is 10-20 MPa, and the pressure is maintained for 20-40 s.

8. The preparation method according to claim 3, characterized in that: In step (6), the sintering process parameters are: first increase the temperature to 500-600 °C at a heating rate of 2-5 °C / min and keep it at that temperature for 1-2 h, then increase the temperature to 900-920 °C at a heating rate of 2-5 °C / min and sinter for 2-4 h, then cool down to 500-600 °C at a heating rate of 2-5 °C / min and cool down naturally to room temperature along with the furnace.

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