本文選題：鈦酸鋇 + XRD　； 參考：《桂林理工大學(xué)》2015年碩士論文

【摘要】：多層陶瓷電容器(Multilayer ceramic capacitor,MLCC)是重要的電子元器件,已廣泛應(yīng)用于移動通信、測量儀器等電子設(shè)備中。隨著微電子工業(yè)和技術(shù)的日新月異,電子元器件的高度集成及微型化迫切需要功能陶瓷材料滿足高介電常數(shù)、低損耗以及較低溫度變化率的要求。目前,大多數(shù)的PbTiO3-基陶瓷材料已經(jīng)應(yīng)用于電容器領(lǐng)域。然而在生產(chǎn)、制備、使用及廢棄處理中,氧化鉛的毒性以及在高溫下容易揮發(fā)等缺點會對環(huán)境和人類社會的可持續(xù)發(fā)展造成極大的破壞。此外,鈦酸鋇(BaTiO3,BT)被認為是應(yīng)用最廣的一種高介電常數(shù)鈣鈦礦鐵電體,但是這類高介質(zhì)陶瓷材料的介電溫度穩(wěn)定性極差,特別是在相變溫度附近介電常數(shù)波動很大,極大地限制了其應(yīng)用。所以,對獲得具有應(yīng)用潛力的寬溫度區(qū)間穩(wěn)定型無鉛高介電陶瓷體系的探索研究是當(dāng)下亟需解決的現(xiàn)實問題,同時,研究無鉛陶瓷體系的介電性能、弛豫機制以及微觀機理是材料科學(xué)與凝聚態(tài)物理學(xué)的交叉點,具有十分重要的理論研究價值。本論文研究依據(jù)摻雜改性思想,采用傳統(tǒng)兩步固相合成法制備了四個不同的陶瓷體系:(1-x)BaTiO3-x Bi(Mg0.75W0.25)O3(BT-BMW)、(1-x)BaTiO3-xBi(Zn0.75W0.25)O3(BT-BZW)、(1-x)BaTi O3-xBi(Mg0.5Zr0.5)O3(BT-BMZ)、(1-x)BaTiO3-xBi(Mg2/3Nb1/3)O3(BT-BMN)無鉛鈦酸鋇基陶瓷體系,并研究了其物相結(jié)構(gòu)、微觀顯微結(jié)構(gòu)、介電性能以及介電常數(shù)溫度穩(wěn)定性。通過系統(tǒng)地對四個不同的陶瓷體系研究表明:BT-BMW、BT-BZW、BT-BMZ和BT-BMN陶瓷體系隨著增加摻雜含量,從正常的鐵電體逐漸轉(zhuǎn)變?yōu)槌谠ヨF電體;在一定的溫度范圍內(nèi),四個體系均具有高介電常數(shù),較低介電損耗以及較小的介電常數(shù)溫度變化率。當(dāng)BT-BMW陶瓷樣品組分為0.07≤x≤0.24時,在200~500℃的溫度范圍內(nèi),具有高介電常數(shù)(2000~5000)、較低介電損耗以及介電常數(shù)的溫度變化率(Δε/ε200o C)在±15%以內(nèi)。當(dāng)BT-BZW陶瓷樣品組分為x=0.04時,在25~125℃的溫度范圍內(nèi),具有高介電常數(shù)(~3000)、較低介電損耗(3%)以及介電常數(shù)的溫度變化率(Δε/ε25o C)在±15%以內(nèi),當(dāng)陶瓷樣品組分為x=0.2的(Δε/ε100o C)同樣也在±15%內(nèi)。當(dāng)BT-BMZ陶瓷樣品為x=0.06和0.08,在200~350℃和200~370℃的溫度范圍內(nèi)均具有高介電常數(shù)(~5000-7000)、較低介電損耗(5%)以及介電常數(shù)的溫度變化率(Δε/ε27o C)在15%以內(nèi),特別對組分為x=0.1,即使測試溫度升高到大約400°C,陶瓷樣品的Δε/ε200o C同樣也在±15%內(nèi),該陶瓷樣品在25~240°C溫度范圍內(nèi),具有穩(wěn)定的高介電常數(shù)(~6800±15%)、較低介電損耗(≤9%)以及介電常數(shù)的溫度變化率(Δε/ε100o C)在15%以內(nèi)。通過摻雜改性,顯著改善了四個陶瓷體系的介電常數(shù)溫度穩(wěn)定性,同時具有高的介電常數(shù)。
[Abstract]:Multilayer ceramic capacitors (MLCC) are important electronic components, which have been widely used in mobile communication, measurement instruments and other electronic devices. With the rapid development of microelectronics industry and technology, the high integration and miniaturization of electronic components urgently need functional ceramics to meet the requirements of high dielectric constant, low loss and low temperature change rate. At present, most of PbTiO 3-based ceramic materials have been used in capacitor field. However, in the production, preparation, use and disposal of waste, the toxicity of lead oxide and the easy volatilization at high temperature will cause great damage to the environment and the sustainable development of human society. In addition, barium titanate BaTiO3B) is considered to be one of the most widely used perovskite ferroelectrics, but the dielectric temperature stability of this kind of high dielectric ceramics is extremely poor, especially in the vicinity of phase transition temperature. Its application is greatly limited. Therefore, it is an urgent problem to explore and study the wide temperature range stable lead-free and high dielectric ceramics system with wide application potential. At the same time, the dielectric properties of lead-free ceramics system are studied. Relaxation mechanism and microscopic mechanism are the intersection of material science and condensed matter physics. In this paper, four different ceramic systems, 1-xBaTiO3-x BiMg0.75W0.75W0.25W0.25O3BT-BMWN-based system, were prepared by conventional two-step solid-state synthesis method, and the phase structure and microstructure of barium titanate were studied. Dielectric properties and temperature stability of dielectric constant. The systematic study of four different ceramic systems shows that the ratio BT-BMW-BT-BZWU BT-BMZ and BT-BMN ceramics gradually change from normal ferroelectrics to relaxor ferroelectrics with the increase of doping content, and the four systems have high dielectric constants in a certain temperature range. Lower dielectric loss and smaller temperature change rate of dielectric constant. When the composition of BT-BMW ceramics is 0.07 鈮，

本文編號：1825895