CN104987070A - Temperature stable microwave dielectric ceramic with medium dielectric constant and preparation method of temperature stable microwave dielectric ceramic - Google Patents

Abstract

_The invention discloses a medium dielectric constant and temperature stable microwave dielectric ceramic material, the chemical _formula of which is: ( _{Zn 0.95} Mg _0.05 ) _{ZrNbTaO 8 ;} (Zn _0.95 Mg _0.05 ZrNbTaO ₈ ingredients, after ball milling, drying, and sieving, pre-fired at 700-850°C, and then ball-milled, dried, and sieved, and pressed into a green body; the green body was heated at 1150°C Sintered at 1280°C to make microwave dielectric ceramics. The dielectric constant ε _r of the present invention is 28.42 to 31.86, the quality factor Q × f is 85345 to 92745 GHz, and the temperature coefficient of resonance frequency τ _f is -8.56 to 3.85 × 10 ^-6 /°C The preparation process is simplified, saving time and energy costs.

Description

Medium dielectric constant temperature stable microwave dielectric ceramic and preparation method thereof

technical field

The invention belongs to a ceramic composition characterized by components, in particular to a microwave dielectric ceramic with a chemical formula of (Zn _0.95 Mg _0.05 )ZrNbTaO ₈ , which has medium dielectric constant and temperature stability, and a preparation method thereof.

Background technique

The continuous development of modern communication technology, especially the development of mobile communication towards high reliability and small size, puts forward higher requirements for microwave dielectric materials. Microwave dielectric ceramics have become one of the most active research fields of functional ceramics in recent years. Among them, the research on temperature stability has become a hot spot. Microwave devices need to work at different temperatures, and to ensure the stability of the carrier signal at different temperatures, it is necessary to require that the resonant frequency of the microwave dielectric material does not change with temperature, or changes slightly. Therefore, the near-zero resonant frequency temperature coefficient has become an important factor to measure the performance of materials.

With the continuous development of ceramic materials, in order to meet different applications, various new materials with excellent performance are emerging. The intermediary niobate microwave dielectric ceramics, centered on ZnO-Nb ₂ O ₅ series microwave dielectric ceramics, has received extensive attention. The (Zn _0.95 Mg _0.05 )ZrNbTaO ₈ of the present invention is a composite microwave dielectric ceramic material with a monoclinic structure, which has good microwave dielectric properties, and there is no relevant report of the present invention at home and abroad.

Contents of the invention

The purpose of the present invention is to adjust the resonant frequency temperature coefficient of the ZnZrNb ₂ O ₈ microwave dielectric material, further improve the quality factor, and meet the needs of the continuous development of electronic information technology in the direction of high frequency and digitalization. Provided is a (Zn _0.95 Mg _0.05 ) ZrNbTaO ₈ microwave dielectric ceramic material with a high quality factor prepared by a simple solid phase method using ZnO, MgO, ZrO ₂ , Nb ₂ O ₅ , and Ta ₂ O ₅ as raw materials.

The present invention is realized through the following technical solutions.

A medium dielectric constant and temperature stable microwave dielectric ceramic material, the chemical formula of which is: (Zn _0.95 Mg _0.05 )ZrNbTaO ₈ ;

The basic method of the microwave dielectric ceramic material, the specific implementation steps are as follows:

(1) Mix ZnO, MgO, ZrO ₂ , Nb ₂ O ₅ , and Ta ₂ O ₅ according to the stoichiometric formula (Zn _0.95 Mg _0.05 ) ZrNbTaO ₈ , put the powder into a polyester tank, add deionized water and After zirconium balls, ball mill for 5-9 hours;

(2) Put the ball-milled raw materials in step (1) into a drying oven, dry them at 100-120°C, and pass through a 40-mesh sieve;

(3) Put the powder sieved in step (2) into a medium-temperature furnace, pre-fire at 700-850°C, and keep warm for 4-8 hours.

(4) Mix the pre-fired powder in step (3), put it into a ball mill tank, add zirconia balls and deionized water, mill for 9 to 12 hours, dry and sieve, and then use a powder tablet machine Press into a green body with a pressure of 5-9MPa;

(5) Sintering the green body in step (4) at 1150° C. to 1280° C. and keeping it warm for 2 to 8 hours to produce a microwave dielectric ceramic with a medium dielectric constant.

The step (1) adopts a planetary ball mill for ball milling, and the ball mill speed is 600 rpm.

The green body in the step (4) has a diameter of 10mm and a thickness of 5mm.

The sintering temperature in the step (5) is 1220°C.

The invention prepares a novel microwave dielectric ceramic material (Zn _0.95 Mg _0.05 ) ZrNbTaO ₈ through a simple solid phase method. Its dielectric constant ε _r is 28.42-31.86, its quality factor Q×f is 85345-92745 GHz, and its resonant frequency temperature coefficient τ _f is -8.56-3.85×10 ^-6 /℃. The preparation method simplifies the preparation process of the material and saves time and energy costs.

Detailed ways

The present invention uses ZnO (analytical pure), NiO (analytical pure), ZrO ₂ (analytical pure), Nb ₂ O ₅ (analytical pure), BaCO ₃ (analytical pure), CuO (analytical pure), H ₃ BO ₃ (analytical pure) Pure) as the initial raw material, the microwave dielectric ceramic (Zn _0.95 Mg _0.05 ) ZrNbTaO ₈ was prepared by a simple solid-state method, and the specific implementation steps were as follows:

1. Mix ZnO, MgO, ZrO ₂ , Nb ₂ O ₅ , and Ta ₂ O ₅ according to the stoichiometric formula (Zn _0.95 Mg _0.05 ) ZrNbTaO ₈ , and the powder ratio is: 2.779053g ZnO, 0.0718g MgO, 4.7774g ZrO ₂ , 7.9422g Nb ₂ O ₅ 4.4292g Ta ₂ O ₅ ; put about 20g of the mixed powder into a polyester tank, add 200ml of deionized water, add 150g of zirconium balls, and mill on a planetary ball mill for 6 hours , the speed is 600 rpm;

2. Put the ball-milled raw materials in a drying oven, dry them at 100°C, and then pass them through a 40-mesh sieve;

3. Put the sieved powder into a medium-temperature furnace, pre-fire it at 700°C, and keep it warm for 4 hours;

4. Mix the pre-fired products in step 3, put them into a ball mill jar, add zirconia balls and deionized water, mill them for 12 hours, dry them and sieve them, and then use a powder tablet press to press them into a compact at a pressure of 6MPa Body, the green body diameter is 10mm, thickness is 5mm;

5. Sinter the green body at 1150-1280°C and keep it warm for 6 hours to make a microwave dielectric ceramic with a medium dielectric constant.

The microwave characteristics of the obtained products were tested by a network analyzer.

The relevant process parameters and microwave dielectric properties of specific embodiments of the present invention are shown in Table 1.

Table 1

Claims (4)

1. a medium dielectric constant microwave medium temperature-stabilized microwave medium ceramic material, its chemical formula is: (Zn _0.95mg _0.05) ZrNbTaO ₈;

This microwave dielectric ceramic materials present method, concrete implementation step is as follows:

(1) by ZnO, MgO, ZrO ₂, Nb ₂o ₅, Ta ₂o ₅stoichiometrically formula (Zn _0.95mg _0.05) ZrNbTaO ₈prepare burden, powder is put into polyester tank, after adding deionized water and zirconium ball, ball milling 5 ~ 9 hours;

(2) raw material after step (1) ball milling is put into loft drier, in 100 ~ 120 DEG C of oven dry, then cross 40 mesh sieves;

(3) moderate oven put into by the powder after step (2) being sieved, and in 700 ~ 850 DEG C of pre-burnings, is incubated 4 ~ 8 hours.

(4) mixed by the powder after step (3) pre-burning, put into ball grinder, add zirconia ball and deionized water, ball milling 9 ~ 12 hours, sieves after oven dry, then is pressed into base substrate with powder compressing machine with the pressure of 5 ~ 9MPa;

(5) by the base substrate of step (4) in 1150 DEG C ~ 1280 DEG C sintering, be incubated 2 ~ 8 hours, make the microwave-medium ceramics with medium dielectric constant microwave medium.

2. medium dielectric constant microwave medium temperature-stabilized microwave medium ceramic material according to claim 1, is characterized in that, described step (1) adopts planetary ball mill to carry out ball milling, and drum's speed of rotation is 600 revs/min.

3. medium dielectric constant microwave medium temperature-stabilized microwave medium ceramic material according to claim 1, is characterized in that, the blank diameter of described step (4) is 10mm, and thickness is 5mm.

4. medium dielectric constant microwave medium temperature-stabilized microwave medium ceramic material according to claim 1, is characterized in that, the sintering temperature of described step (5) is 1220 DEG C.