本文選題：微波介質(zhì)陶瓷 + 低介電常數(shù)�。� 參考：《桂林理工大學(xué)》2017年碩士論文

【摘要】：隨著現(xiàn)代通信技術(shù)的飛速發(fā)展,微波技術(shù)向著更高頻率的方向發(fā)展,同時(shí)微波電子元器件也不斷呈現(xiàn)出高頻化、集成化的特點(diǎn),低介電微波介質(zhì)陶瓷材料受到了越來(lái)越多的關(guān)注。本文系統(tǒng)研究了(1-x)Zn Al2O4-x Li4/3Ti5/3O4、Li4x/3Zn2-2x Ti1+2x/3O4、Li_(4x/3)Mg_(2-2x)Ti_(1+2x/3)O_4、Ba_4CuTi_(11)O_(27)等低介電微波介質(zhì)陶瓷的制備及性能,探究了Li_2ZnTi_3O_8、Li_2MgTi_3O_8陶瓷的工藝優(yōu)化,并對(duì)上述陶瓷與Ag電極的低溫共燒進(jìn)行了初步探討。(1)利用固相反應(yīng)法制備了(1-x)ZnAl_2O_(4-x)Li_(4/3)Ti_(5/3)O_4(ZALT)(x=0.2,0.4,0.6,0.8)微波介質(zhì)陶瓷。X射線衍射數(shù)據(jù)顯示,Li_4Ti_5O_(12)和Zn Al2O4不能形成固溶體。隨著x從0.2增加至0.8,ZALT陶瓷的相組成發(fā)生了如下變化:(Zn Al2O4和Li_2ZnTi_3O_8,x=0.2,0.4)→(Zn Al2O4,Li_2ZnTi_3O_8和Li_4Ti_5O_(12),x=0.6)→(Li_2ZnTi_3O_8和Li_4Ti_5O_(12),x=0.8)。隨著x值的增加,燒結(jié)溫度從1275°C降低到1075°C。ZALT陶瓷的微波介電性能表現(xiàn)為,ε_(tái)r:11.0~29.0,品質(zhì)因數(shù)Q×f值:6,090~65,580 GHz,溫度系數(shù)τ_f值:-62.9~-5.7 ppm/°C。(2)通過(guò)傳統(tǒng)的固相法分別制備了Li_(4x/3)Zn_(2-2x)Ti_(1+2x/3)O_4(0.2≤x≤0.8)(LZT)、Li_(4x/3)Mg_(2-2x)Ti_(1+2x/3)O_4(0.2≤x≤0.8)(LMT)微波介質(zhì)陶瓷。XRD分析表明,當(dāng)0.2≤x≤0.4時(shí),樣品分別表現(xiàn)為Zn2Ti O4結(jié)構(gòu)、Mg2Ti O4結(jié)構(gòu)的固溶體,當(dāng)0.6≤x≤0.8時(shí),固溶體的結(jié)構(gòu)分別改變?yōu)長(zhǎng)i_2ZnTi_3O_8結(jié)構(gòu)、Li_2MgTi_3O_8結(jié)構(gòu)。隨著x值的增加,陶瓷的燒結(jié)溫度有所下降,其溫度系數(shù)τ_f值從較大的負(fù)值增加到接近于零。LZT、LMT陶瓷均表現(xiàn)優(yōu)異的微波介電性能(LZT:ε_(tái)r:12.6~26.3,Q×f:7930130560GHz,τ_f:-49.0~-14.0ppm/°C;LMT:ε_(tái)r:11.6~29.3,Q×f:22000～172670GHz,τ_f:-48.9~-3.9 ppm/°C)。此外,LZT(x=0.8)、LMT(x=0.8)分別可以在925℃、950 ℃與Ag粉具有很好的化學(xué)兼容性。(3)系統(tǒng)研究了原材料預(yù)處理對(duì)Li_2ZnTi_3O_8陶瓷、Li_2MgTi_3O_8陶瓷的顯微結(jié)構(gòu)、燒結(jié)特性及微波介電性能的影響,恰當(dāng)?shù)脑牧项A(yù)處理使得陶瓷在一個(gè)較低的溫度區(qū)間(Li_2ZnTi_3O_8:950~1050 ℃,Li_2MgTi_3O_8:925~1075 ℃)獲得高的品質(zhì)因數(shù),改善了陶瓷的燒結(jié)特性,降低其燒結(jié)溫度,而且在一定程度上也對(duì)其τ_f值進(jìn)行了調(diào)節(jié)。950 ℃燒結(jié)的Li_2ZnTi_3O_8陶瓷與925 ℃燒結(jié)的Li_2MgTi_3O_8陶瓷均能夠能與Ag共燒兼容,并表現(xiàn)出優(yōu)異的微波介電性能:ε_(tái)r=25.8,Q×f=74,200 GHz,τ_f=-13 ppm/℃(Li_2ZnTi_3O_8);ε_(tái)r=27.0,Q×f=58,480 GHz,τ_f=0.45ppm/℃(Li_2MgTi_3O_8)。(4)采用固相反應(yīng)法制備了新型Ba_4CuTi_(11)O_(27)低燒微波介質(zhì)陶瓷,通過(guò)Rietveld法對(duì)975 ℃燒結(jié)的樣品進(jìn)行XRD精修,可以確定這個(gè)純化合物為單斜晶相,空間群為C12/m,其相結(jié)構(gòu)為Ba_4CuTi_(11)O_(27),可靠因子分別為RWP=6.1%,RP=4.6%,RB=3.1%。當(dāng)燒結(jié)溫度為975 ℃時(shí),陶瓷具有較為優(yōu)異的微波介電性能:ε_(tái)r~36.3,Q×f~15,040 GHz,τ_f~11.9ppm/℃。Ba_4CuTi_(11)O_(27)在950 ℃時(shí)也表現(xiàn)出較好的微波性能,并且可以與Ag電極表現(xiàn)出良好的化學(xué)兼容性。
[Abstract]:With the rapid development of modern communication technology, microwave technology is developing to a higher frequency. At the same time, microwave electronic components have the characteristics of high frequency and integration. Low dielectric microwave dielectric ceramics have attracted more and more attention. In this paper, we have systematically studied the preparation and properties of low-dielectric microwave dielectric ceramics such as Li4x3Zn2-2x Ti1 2x3O4L, Li4x / Zn / 3Zn2-2x, Li4x / 3Zn2-2O4, Li-x / 3Mg-P / 3M / T, 4 x / 3Mg-TiV, 12x- / 3mq, Ba4CuTiV, etc., and investigated the technological optimization of Li2ZnTi3O8 / Li2ZnTi3O8. The low temperature co-firing of the above mentioned ceramics and Ag electrode was discussed. 1) the solid state reaction method was used to prepare 1-xZnAl2O2O-4-xAl2O-4 / 3tititititititi-5 / 3O4 / 5 / 3O4ZALTX 0.2O0.40.60.8. the microwave dielectric ceramics. X-ray diffraction data show that Li4Ti5OSAS12) and Zn Al2O4 can not form solid solutions. As the phase composition of ZALT ceramics increases from 0.2 to 0.8, the following changes have taken place in the phase composition of the ZALT ceramics: Zn / Zn Al2O4 and Li _ 4Ti _ 5i _ 3O _ 3O _ (0.2o).) Zn Al _ 2O _ 4o _ 3O _ 8 and Li _ 4Ti _ 5O _ 3O _ 2O _ 8 and Li4Ti5O _ (0. 6). As the x value increases, 鐑х粨娓╁害浠，

本文編號(hào)：1919676