CN102491734A

CN102491734A - Medium high-Q microwave dielectric ceramics and preparation method thereof

Info

Publication number: CN102491734A
Application number: CN2011104035398A
Authority: CN
Inventors: 郑兴华; 梁炳亮; 汤德平
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2011-12-08
Filing date: 2011-12-08
Publication date: 2012-06-13
Anticipated expiration: 2031-12-08
Also published as: CN102491734B

Abstract

The invention discloses medium high-Q microwave dielectric ceramics and a preparation method thereof. The composition expression of the medium high-Q microwave dielectric ceramics is xCaO-y(mLa2O3-nLn2O3)-z(pMgO-qTiO2), wherein Ln=La, Nd and Sm, the content of each component in molar percentage is respectively as follows: x is not less than 0mol% and not more than 35.1mol%, y is not less than 7.5mol% and not more than 33.3mol%, z is not less than 57.5mol% and not more than 66.7mol%, x+y+z=100mol%, m+n=1 and p+q=1. Raw materials adopted in a product disclosed by the invention do not contain Pb, Bi, Cd and other components which can harm the health of human bodies and pollute an environment, and the product has a medium dielectric constant, a high Qf value and a near-zero resonant frequency temperature coefficient, is extensive in raw material source, low in price and suitable for dielectric resonators, wave filters, oscillators, capacitors and other electronic components in systems for mobile communication, satellite communication and the like, and can be widely applied in the fields of satellite broadcast televisions, global satellite positioning systems, Bluetooth technologies and the like.

Description

Intermediary's high-Q microwave dielectric pottery and preparation method thereof

Technical field

The invention belongs to electronic information material and devices field, be specifically related to intermediary's high-Q microwave dielectric pottery that is applied to crucial microwave devices such as microwave telecommunication system medium resonator, wave filter, vibrator and electrical condenser and preparation method thereof.

Background technology

In recent years; Fast development along with mobile communication and satellite communication; Microwave devices such as the dielectric resonator that the employing microwave-medium ceramics is made, wave filter, vibrator, electrical condenser have advantages such as volume is little, light weight, stable performance, low price; Therefore, surging to the increasing demand of corresponding microwave-medium ceramics.

Microwave communication is towards high frequency, high-quality, miniaturized development, press for have medium specific inductivity (40 ~ 60), the microwave-medium ceramics of hi-q and stable resonant frequency temperature profile.Such microwave-medium ceramics of using at present mainly is (Zr, Sn) TiO ₄, BaTi ₄O ₉/ Ba ₂Ti ₉O ₂₀And CaTiO ₃-NdAlO ₃, specific inductivity is relatively low, the control of technology relative difficult but exist.Therefore, press for intermediary's high-Q microwave dielectric pottery that development and preparation technology is simple, specific inductivity is higher, to satisfy the requirement of related application.

Summary of the invention

The intermediary's high-Q microwave dielectric pottery that the object of the present invention is to provide a kind of high dielectric constant, hi-q and have stable resonant frequency temperature profile, the preparation method is simple, and is workable, and raw material is easy to get, and cost is low.

For realizing above-mentioned purpose, the present invention adopts following technical scheme:

A kind of intermediary high-Q microwave dielectric pottery, its composition expression formula does xCaO- y(mLa ₂O ₃- nLn ₂O ₃)- z( pMgO- qTiO ₂), wherein Ln=La, Nd, Sm, x+ y+ z=100mol%, m+ n=1, p+ q=1, the mole percent level of each composition is respectively:

Quicklime (CaO) 0mol%≤ x≤35.1mol%;

Lanthanum trioxide (La ₂O ₃), Neodymium trioxide (Nd ₂O ₃) and Samarium trioxide (Sm ₂O ₃) 7.5mol%≤ y≤33.3mol%, wherein

Lanthanum trioxide (La ₂O ₃) 0mol%-33.3mol%

Neodymium trioxide (Nd ₂O ₃) 0mol%-33.3mol%

Samarium trioxide (Sm ₂O ₃) 0mol%-33.3mol%

Natural manganese dioxide (MgO) and titanium oxide (TiO ₂) 57.5mol%≤ z≤66.7mol%, wherein

Natural manganese dioxide (MgO) 0mol%-33.3mol%

Titanium oxide (TiO ₂) 33.3mol%-57.5mol%.

Preferred ingredient is:

(1) Ln=La，11.6mol%≤ x≤25.6mol%，14.4mol%≤ y≤24.7mol%，60.0mol%≤ z≤63.6mol%，0.10≤ m≤0.38，0.62≤ n≤0.90，0.15≤ p≤0.35，0.65≤ q≤0.85；

(2) Ln=Nd，11.6mol%≤ x≤28.8mol%，12.1mol%≤ y≤24.7mol%，59.1mol%≤ z≤63.6mol%，0.10≤ m≤0.51，0.49≤ n≤0.90，0.10≤ p≤0.35，0.65≤ q≤0.90；

(3) Ln=Sm，15.3mol%≤ x≤28.8mol%，12.1mol%≤ y≤22.1mol%，59.1mol%≤ z≤62.7mol%，0.15≤ m≤0.51，0.49≤ n≤0.85，0.10≤ p≤0.30，0.60≤ q≤0.90。

Best composition and be respectively by the best microwave dielectric property that microwave-medium ceramics had that corresponding prescription obtains:

(1) Ln=La， x=22.3mol%， y=16.9mol%， z=60.8mol%， m=0.28， n=0.72， p=0.20， q=0.80；e=42，Qf=38900GHz，t _f=-20×10 ^-6/℃；

(2) Ln=Nd， x=25.6mol%， y=14.4mol%， z=60.0mol%， m=0.38， n=0.62， p=0.15， q=0.85；e=48，Qf=28000GHz，t _f=-7×10 ^-6/℃；

(3) Ln=Sm， x=25.6mol%， y=14.4mol%， z=60.0mol%， m=0.38， n=0.62， p=0.15， q=0.85；e=51，Qf=42200GHz，t _f=-10×10 ^-6/℃。

Intermediary of the present invention high-Q microwave dielectric pottery adopts the conventional solid reaction process preparation of electronic ceramic fields, and concrete grammar is following: by CaO, La in the component ₂O ₃, Ln ₂O ₃, MgO, TiO ₂The molar content ratio get raw materials of Ca CO ₃, La ₂O ₃, La ₂O ₃Or Nd ₂O ₃Or Sm ₂O ₃, MgO and TiO ₂Mix 8 ~ 24h with zero(ppm) water for the medium wet ball grinding; Oven dry back pre-burning 2 ~ 6h in 1150 ~ 1450 ℃, air atmosphere obtains preburning powder; In preburning powder, add sticker granulation, press ceramic base substrate then, the ceramic body that makes is sintering 2 ~ 6h in 1400 ~ 1650 ℃, fluidizing air atmosphere, obtains described intermediary high-Q microwave dielectric pottery.Said sticker is for be applicable to the sticker polyvinyl alcohol solution of pottery preparation usually.

Remarkable advantage of the present invention is: intermediary provided by the invention high-Q microwave dielectric pottery; The raw material that adopts does not contain the composition of any infringement HUMAN HEALTH, contaminate environment; And having medium specific inductivity e is 30 ~ 70, and high Qf value is 18000 ~ 52000GHz and nearly zero temperature coefficient of resonance frequency.The critical material that can be used as electronic devices and components such as microwave communication medium resonator, wave filter, vibrator and electrical condenser uses; Can be widely used in fields such as satellite broadcasting television, Global Positioning System and Bluetooth technology, have great industrial application value.

Embodiment

Further describe the present invention below in conjunction with specific embodiment, but protection scope of the present invention is not limited in the following example:

Be the CaCO more than the 99.5wt% at first with purity ₃, La ₂O ₃, La ₂O ₃Or Nd ₂O ₃Or Sm ₂O ₃, MgO and TiO ₂Molar content by each embodiment in the table 1 is that medium mixes 12-24h with wet milling process than with zero(ppm) water, oven dry back pre-burning 3h in 1150 ~ 1450 ° of C, air atmosphere; After in preburning powder, adding Z 150PH (PVA) aqueous solution (concentration the is 5wt%) granulation of 8wt% then; Press down the ceramic body of processing diameter 13mm, thickness 2 ~ 6mm at 100MPa pressure, sintering 2-6h obtains described intermediary high-Q microwave dielectric pottery in 1400 ~ 1650 ° of C, fluidizing air atmosphere at last.Microwave dielectric property with ceramic sample behind the network analyzer test sintering.

The relation of the microwave-medium ceramics composition and performance among the embodiment is as shown in table 1.

The composition and performance of table 1 microwave-medium ceramics

Figure 2011104035398100002DEST_PATH_IMAGE002

Can know by table 1, in microwave-medium ceramics system of the present invention, along with the minimizing, (La of CaO content ₂O ₃+ Ln ₂O ₃) (Ln=La, Nd, Sm) and (MgO+TiO ₂) increase of content, specific inductivity e is tending towards reducing, temperature coefficient of resonance frequency t _fBy just changeing negative, Qf value (Q is quality factor, and f is a resonant frequency) increases afterwards earlier and reduces.

In the embodiment of the invention 1 ~ 16, best composition and be respectively by the best microwave dielectric property that microwave-medium ceramics had that corresponding prescription obtains:

The above is merely preferred embodiment of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.

Claims

1. intermediary's high-Q microwave dielectric is ceramic, and it is characterized in that: the composition expression formula of described microwave-medium ceramics is: xCaO- y(mLa ₂O ₃- nLn ₂O ₃)- z( pMgO- qTiO ₂), Ln=La, Nd or Sm, wherein x+ y+ z=100mol%, m+ n=1, p+ q=1, the mole percent level of each component is respectively:

Quicklime (CaO) 0mol%≤ x≤35.1mol%;

Lanthanum trioxide (La ₂O ₃) 0mol%-33.3mol%

Neodymium trioxide (Nd ₂O ₃) 0mol%-33.3mol%

Samarium trioxide (Sm ₂O ₃) 0mol%-33.3mol%;

Natural manganese dioxide (MgO) 0mol%-33.3mol%

Titanium oxide (TiO ₂) 3.3mol%-57.5mol%.

2. intermediary according to claim 1 high-Q microwave dielectric pottery is characterized in that:

Ln=La，11.6mol%≤ x≤25.6mol%，14.4mol%≤ y≤24.7mol%，60.0mol%≤ z≤63.6mol%，0.10≤ m≤0.38，0.62≤ n≤0.90，0.15≤ p≤0.35，0.65≤ q≤0.85；

Ln=Nd，11.6mol%≤ x≤28.8mol%，12.1mol%≤ y≤24.7mol%，59.1mol%≤ z≤63.6mol%，0.10≤ m≤0.51，0.49≤ n≤0.90，0.10≤ p≤0.35，0.65≤ q≤0.90；

Ln=Sm，15.3mol%≤ x≤28.8mol%，12.1mol%≤ y≤22.1mol%，59.1mol%≤ z≤62.7mol%，0.15≤ m≤0.51，0.49≤ n≤0.85，0.10≤ p≤0.30，0.60≤ q≤0.90。

3. intermediary according to claim 2 high-Q microwave dielectric pottery is characterized in that:

Ln=La， x=22.3mol%， y=16.9mol%， z=60.8mol%， m=0.28， n=0.72， p=0.20， q=0.80；

Ln=Nd， x=25.6mol%， y=14.4mol%， z=60.0mol%， m=0.38， n=0.62， p=0.15， q=0.85；

Ln=Sm， x=25.6mol%， y=14.4mol%， z=60.0mol%， m=0.38， n=0.62， p=0.15， q=0.85。

4. intermediary according to claim 1 high-Q microwave dielectric pottery, it is characterized in that: the specific inductivity of described microwave-medium ceramics is 40-52, the Qf value is 28000-52000GHz.

5. intermediary according to claim 1 high-Q microwave dielectric pottery, it is characterized in that: described microwave-medium ceramics has calcium titanium ore structure.

6. the preparation method of an intermediary as claimed in claim 1 high-Q microwave dielectric pottery, it is characterized in that: described preparing method's concrete steps are:

By CaO, La in the component ₂O ₃, Ln ₂O ₃, MgO and TiO ₂The molar content ratio take by weighing raw materials of Ca CO ₃, La ₂O ₃, La ₂O ₃Or Nd ₂O ₃Or Sm ₂O ₃, MgO and TiO ₂

With the powder that weighs up ball mill mixing 8-24h in zero(ppm) water, oven dry then;

Powder after oven dry pre-burning 2-6h in 1150-1450 ℃, air atmosphere obtains uhligite phase powder;

Add sticker granulation, press ceramic base substrate in the pre-burning powder; Described sticker is that concentration is the polyvinyl alcohol solution of 5wt%, and addition is 5 ~ 10% of a preburning powder total mass;

The ceramic body that makes sintering 2-6h in 1400-1650 ℃, fluidizing air obtains the microwave-medium ceramics of specific density more than 98%.