CAJ | 학술논문

以分析纯的Ba(NO3)2、Sr(NO3)2、草酸和钛酸丁酯为原料,采用草酸盐共沉淀法制备了钛酸锶钡(Ba0.6Sr0.4tiO3,BST)纳米粉体.XRD和SEM分析结果表明,该方法制备出立方相的Ba0.6Sr0.4TiO3粉体,平均粒径小于100 nm,具有较高的烧结活性.用传统固相法制备了锰掺杂钛酸锶钡.钛酸镁(Ba0.6Sr0.4TiO3-MgTiO3,BST-MT)复相陶瓷,系统研究了掺杂0.1%-2.0%(x,摩尔分数,下同)锰对钛酸锶钡-钛酸镁复相陶瓷微观形貌和介电性能的影响机理.结果表明,当锰的掺杂量小于1.5%时,Mn作为受主掺杂取代占据钙钛矿ABO3的B位,因此导致居里点略微向高温偏移和相变扩散的发生,锰的掺杂导致晶格畸变,促进了晶粒生长,使晶界相比例下降,因此介电损耗随着锰掺杂量的增大而减小;当锰的掺杂量为1.5%时,介电损耗达到最小值,继续增大掺杂量,介电常数下降,介电损耗上升.
이분석순적Ba(NO3)2、Sr(NO3)2、초산화태산정지위원료,채용초산염공침정법제비료태산송패(Ba0.6Sr0.4tiO3,BST)납미분체.XRD화SEM분석결과표명,해방법제비출립방상적Ba0.6Sr0.4TiO3분체,평균립경소우100 nm,구유교고적소결활성.용전통고상법제비료맹참잡태산송패.태산미(Ba0.6Sr0.4TiO3-MgTiO3,BST-MT)복상도자,계통연구료참잡0.1%-2.0%(x,마이분수,하동)맹대태산송패-태산미복상도자미관형모화개전성능적영향궤리.결과표명,당맹적참잡량소우1.5%시,Mn작위수주참잡취대점거개태광ABO3적B위,인차도치거리점략미향고온편이화상변확산적발생,맹적참잡도치정격기변,촉진료정립생장,사정계상비례하강,인차개전손모수착맹참잡량적증대이감소;당맹적참잡량위1.5%시,개전손모체도최소치,계속증대참잡량,개전상수하강,개전손모상승.
Barium strontium titanate(Ba0.6Sr0.4TiO3,BST)nano-powders were prepared using Ba(NO3)2,Sr(NO3)2, oxalic acid dehydrate,and tetrabutyl titanate(Ti(OC4H9)4)as precursors by the chemical co-precipitation method.The product was characterized by thermogravimetry-differential scanning calorimetry(TG-DSC)thermal analyses,X-ray diffraction(XRD),and scauning electron microscopy(SEM).The experimental results indicated that the resulting Ba0.6Sr0.4TiO3 nano-powders were homogeneous with agglomerated nature.The Ba0.6Sr0.4TiO3-MgTiO3(BST-MT)bulk composite ceramics doped by Mn were obtained by the traditional solid phase method.The XRD patterns demonstrated that Mn-doped BST was unable to change the perovskite crystalline structure of BST materials.SEM photographs revealed that the crystalline grains became larger with increasing the content of doping Mn(<1.5%(x,molar fraction)) and then the size of grains decreased after the Mn content exceeded 1.5% in the BST ceramics.suggesting the effect of Mn doping on the morphologies of BST-MT composites.The dielectric properties of BST-MT composite ceramics doped with 0.1%-2.0%(X)Mn Were investigated systematically.Two effects of Mn doping on the dielectric properties of the BST-MT composite ceramics were observed.At low Mn doping concentrations(<1.5%),Mn mainly acted as an acceptor dopant to replace Ti at the B site of ABO3 perovskite structure,leading to a diffused phase transition.It was also observed that the grain size increased drastically as the Mn content increased and thus caused the decrease of dielectric loss.At higher Mn doping concentrations(>1.5%),the grain size decreased and the suppression of permittivity and the drastic increase of the dielectric losses were observed,which indicated a"composite"mixing effect.