玻璃陶瓷微結(jié)構(gòu)和性能的影響
(1. 桂林電子科技大學(xué) 材料科學(xué)與工程學(xué)院，桂林 541004；
2. 桂林電子科技大學(xué) 廣西信息材料重點(diǎn)實(shí)驗(yàn)室，桂林 541004)
摘 要: 采用熔融法制備NaO-BaO-SrO-Nb2O5-B2O3-SiO2玻璃陶瓷。借助DSC、XRD、SEM和電學(xué)性能測(cè)試研究不同含量的Na2O對(duì)其相組成、顯微結(jié)構(gòu)、介電性能、體積電阻率及擊穿強(qiáng)度的影響。結(jié)果表明：隨著Na2O含量(摩爾分?jǐn)?shù))的增加，玻璃轉(zhuǎn)變溫度(Tg)和第一析晶放熱峰(Tp1)溫度逐漸降低，而第二析晶放熱峰溫度(Tp2)呈先降低后升高再降低的變化。經(jīng)(800 ℃，3 h)+(900 ℃，3 h)熱處理后，未添加Na2O的樣品析出單相四方鎢青銅結(jié)構(gòu)的Ba0.5Sr0.5Nb2O6，而添加5%Na2O(摩爾分?jǐn)?shù))的樣品變?yōu)閱蜗郆a0.25Sr0.75Nb2O6。當(dāng)Na2O為10%時(shí)，樣品的主晶相仍為Ba0.25Sr0.75Nb2O6，但析出NaSr1.2Ba0.8Nb5O15和Na2Ba2Si2O7相；繼續(xù)增加Na2O量到15%時(shí)，樣品的晶相種類不變而衍射峰強(qiáng)度有所增強(qiáng)。樣品的介電常數(shù)隨Na2O含量的增加呈“N”字形變化，樣品的體積電阻率和擊穿強(qiáng)度隨Na2O含量的增加而降低，未添加Na2O試樣的擊穿強(qiáng)度最大為1 500 kV/cm, 其儲(chǔ)能密度達(dá)3 J/cm3。
關(guān)鍵字: 玻璃陶瓷；電學(xué)性能；微結(jié)構(gòu)；擊穿強(qiáng)度；儲(chǔ)能密度
（1. School of Mater, ials Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, China;
2. Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China）
Abstract:NaO-BaO-SrO-Nb2O5-B2O3-SiO2 glass-ceramics were prepared using melting method. The effects of different Na2O contents on the phase compositions, microstructure, dielectric properties, volume resistivity and breakdown strength were investigated by differential scanning calorimetry (DSC), X-ray diffractometry (XRD), scanning electric microscopy (SEM) and electrical property measurements. The results show that with increasing Na2O content, the glass transition temperature (Tg) and the first crystallization peak temperature (Tp1) gradually decrease, but the second crystallization peak temperature (Tp2) firstly decreases and then increases and finally decreases. Under the same heat treatment condition ((800 ℃, 3 h)+(900 ℃, 3 h)), the single phase tetragonal tungsten bronze Ba0.5Sr0.5Nb2O6 occurs in the sample without Na2O. The pure phase, Ba0.25Sr0.75Nb2O6, is obtained when Na2O content (mole fraction) is 5%. As Na2O content (mole fraction) is 10%, the main crystalline phase is still Ba0.25Sr0.75Nb2O6, however, the phases of NaSr1.2Ba0.8Nb5O15 and Na2Ba2SiO6 appear. For the sample with 15%Na2O, the types of the crystalline phases are unchanged, but the intensity of the diffraction peak slightly increases. With increasing Na2O content, the dielectric constant of glass-ceramics changes like a “N” letter, while the breakdown strength and volume resistivity decrease. The sample without Na2O has the highest breakdown strength (1 500 kV/cm), and its energy storage density is 3 J/cm3.
Key words: glass-ceramic; electrical properties; microstructure; breakdown strength; energy density
