摘要
研究了制备纯钙钛矿相0.80Pb(Mg1/3Nb2/3)O3-0.20PbTiO3(缩写为PMNT)陶瓷的半化学法新工艺.详细讨论了除Nb2O5外,其它反应物以其非氧化物形态分别代替PbO、MgO和TiO2,以及PbTiO3或同成分的0.80PMN-0.20PT等钙钛矿相子晶对PMNT预烧粉体中钙钛矿相含量的影响;探讨了烧结温度对半化学法制备的PMNT陶瓷介电性能的影响,并对PMNT陶瓷的相组成、显微组织及介电性能进行了表征和测定.结果表明:提高镁组分的反应活性对提高预烧粉体中钙钛矿相含量的效果较好,同时以钛酸四丁酯取代TiO2的效果最好;半化学法工艺简单,能在850℃/2h预烧条件下制得几乎纯钙钛矿相的PMNT粉体,经过较低的烧结温度(950℃/2h)可制得致密的、介电性能优异的PMNT陶瓷.
A semichemical method (SCM) was developed for synthesizing 0.80Pb(Mg1/3Nb2/3)O-3-0.20PbTiO(3) (PMNT) with pure perovskite phase. The influences of the chemical reactivities of the partial starting materials, such as soluble Mg-salts instead of MgO, Pb-salts instead of PbO and Ti(OC4H9)(4) instead of TiO2 and crystalline of pure perovskite phase of PMNT on the formation of perovskite phase were investigated in detail. The influences of technological parameters, such as calcining temperature, sintering temperature and soaking time, on the phase content, and dielectric properties were investigated systematically. The results show that Mg-salts are effective for the formation of perovskite phase, especially Mg(NO3)(2) and/or Mg(AC)(2) instead of MgO in a molecular grade. Almost pure perovskite phase can be obtained by both using Mg(NO3)(2) and Ti(C4H9O)(4) instead of MgO and TiO2 respectively. The optimum preparation parameters are the calcining condition of 850 degreesC/2h and the sintering condition of 950 degreesC/2h. The semichemical method has many advantages of not only simple preparation process, lowing calcining and sintering temperatures, shorting reacting time, but also preparing ceramics with excellent dielectric properties. The sintered ceramics having clear crystal boundaries, large-sized crystal grains and high density, and pure perovskite phase of PMNT were successfully prepared by the SCM.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2004年第6期1313-1321,共9页
Journal of Inorganic Materials
基金
陕西高校省级重点实验室重点科研基金(02JS12)
陕西省自然科学基金(2001H06)
西北大学校内基金(00NW41)
关键词
半化学法
弛豫铁电陶瓷
钙钛矿相
介电性能
semichemical method
relaxor ferroelectrics
perovskite phase
dielectric properties
