制备工艺对钛酸钡基无铅高压陶瓷电容器材料性能的影响

以BaTiO3为基料,加入SrTiO3,CaCO3,Bi2O3·3TiO2等制备了(1-z)Ba1-x-ySrxCayTiO3·z(Bi2O3·3TiO2)系无铅高压陶瓷电容器材料,研究了制备工艺对材料性能的影响.结果表明,在保温时间一定的情况下,瓷料的最佳烧结温度取决于组分中Bi2O3·3TiO2含量,且烧结温度随着Bi2O3·3TiO2的含量的增加而降低;在BaTiO3中加入30％SrTiO3,10％ CaCO3和3％ Bi2O3·3TiO2时(均为摩尔分数),瓷料的最佳烧结温度为1240℃,其εr=3802,tgδ=4.2×10-3,Eb=9.2 kV·mm-1;并且在研究介温性能时,居里温度降低到35℃左右,拓宽了介电峰;当Bi2O3·3TiO2的含量增加到4％时,瓷料的最佳烧结温度为1220℃;在合理的烧结温度范围内,低温烧结和慢速升温将有利于细晶的致密化,从而改善高压陶瓷电容器的综合性能.     

Study on Dy2O3-Doped Medium Temperature Sintering (Ba,Sr)TiO3 Series Capacitor Ceramics

The influence of Dy₂O₃ doping on the properties of medium temperature sintering (Ba, Sr)TiO₃ series capacitor ceramics was studied by single factor various amount method, and the law of the influence on the medium temperature sintering (Ba, Sr)TiO₃ series capacitor ceramics was obtained. The dielectric materials used for multilayer ceramic capacitor was obtained, of which the dielectric constant was 1375, the dielectric loss was 0.0060, the density was 5.92 g·cm⁻³, the sintering temperature was less than 1150 °C, the capacitance temperature changing rate (ΔC/C) was less than ± 15%, the voltage withstand strength was more than 9.3 kV·mm⁻¹, and the crystal grain size was about 1 μm. The surface morphology of the sample doped with various amount Dy₂O₃ was analyzed by scanning electron microscope (SEM). The results showed that doping Dy₂O₃ could form defect solid solution, stop grain growth, fine crystal grain, widen curie peak, obtaining high dielectric constant and low dielectric loss, capacitance temperature property was suited for X7R character, in the (Ba,Sr)TiO₃ series ceramics. At the same time, the voltage withstand strength was enhanced greatly.     

Influence of Composition on Properties of Medium Temperature Sintering （Ba, Sr）TiO3 Series Capacitor Ceramics

The influence of the composition (Yb2O3, MgO, CeO2, Li2CO3) on the dielectric properties of medium temperature sintering (Ba,Sr)TiO3(BST) series capacitor ceramics was investigated by means of conventional technology process and orthogonal design experiments. The major secondary influencing factors and the influencing tendency of various factor′s levels for the dielectric properties of BST ceramics were obtained. The optimum formula for maximum dielectric constant (ε) and for minimum dielectric loss (tanδ) was obtained under the experimental conditions. The BST ceramics with optimum comprehensive properties was obtained by means of orthogonal design experiments, with the sintering temperature at 1200 ℃, the dielectric constant 5239, the dielectric loss 0.0097, withstand electric voltage over 6 MV·m-1, capacitance temperature changing rate (ΔC/C) -75.67%, and suited for Y5V character. The mechanism of the influence of various components on the dielectric properties of medium temperature sintering BST ceramics was studied, thus providing the basis for preparation of multilayer capacitor ceramics and single-chip capacitor ceramics.     

Synthesis of Long Afterglow Phosphors MAl2O4:Eu2+, Dy3+(M=Ca, Sr, Ba) by Microemulsion Method and Their Luminescent Properties

Long afterglow phosphors MAl2O4:Eu2 , Dy3 (M=Ca, Sr, Ba) were synthesized by microemulsion method, and their crystal structure and luminescent properties were compared and investigated. XRD patterns of samples indicate that phosphors CaAl2O4:Eu2 , Dy3 and SrAl2O4:Eu2 , Dy3 are with monoclinic crystal structure and phosphor BaAl2O4:Eu2 , Dy3 is with hexagonal crystal structure. The wide range of excitation spectrum of phosphors MAl2O4:Eu2 , Dy3 (M=Ca,Sr,Ba) indicates that the luminescent materials can be excited by light from ultraviolet ray to visible light and the maximum emission wavelength of phosphors MAl2O4:Eu2 , Dy3 (M=Ca, Sr, Ba) is found mainly at λem of 440 nm (M=Ca), 520 nm (M=Sr) and 496 nm (M=Ba) respectively, the corresponding colors of emission light are blue, green and cyna-green respectively. The afterglow decay tendency of phosphors can be summarized as three processes: initial rapid decay, intermediate transitional decay and very long slow decay. Afterglow decay curves coincide with formula I=At-n, and the sequence of afterglow intensity and time is Sr＞Ca＞Ba.     

掺杂不同质量分数Y_2O_3、MgO对Al_2O_3陶瓷显微结构及介电性能的影响

利用放电等离子烧结技术制备了不同质量分数Y_2O_3单独掺杂及不同质量分数Y_2O_3、MgO共同掺杂的Al_2O_3陶瓷,研究了烧结助剂掺杂质量分数对Al_2O_3陶瓷显微结构及介电性能的影响。结果表明,孔隙率是影响Al_2O_3陶瓷介电性能的主要因素;单独掺杂质量分数为0.25% Y_2O_3时,Al_2O_3陶瓷得到最优的介电性能,介电常数(ε_r)为9.5±0.2,介质损耗(tanδ)稳定在10~(-3)数量级以内;同时掺杂Y_2O_3和MgO能进一步改善其介电性能,当两者质量分数均为0.25%时,得到最优值,介电常数(ε_r)为10.3±0.2,介质损耗(tanδ)稳定在8×10~(-4)以下。     

Sm2O3掺杂BSTN陶瓷的制备与介电性能

采用溶胶凝胶法制备了Sm3+掺杂(Ba,Sr)TiO3/(Ba,Sr)Nb2O6复相陶瓷,XRD衍射表明,样品由钙钛矿相和钨青铜相组成,无其他杂相生成。随着Sm3+掺杂量的增加,样品衍射峰向小角度方向移动,表明掺杂的Sm3+取代了体系中Nb5+及Ti4+。检测了样品的介电-温度性能,结果表明,随着Sm3+掺杂量的增加,样品的介电常数及介电损耗都有所降低,当Sm3+掺杂量达到0.004时,样品介电损耗最低,再增加Sm3+的掺杂量,样品的介电损耗又出现增加的趋势。可以得出,适量Sm3+的掺杂可以有效降低样品的介电损耗。     

Effects of Nd, Sm, Gd, Dy, Er Dopant on Electrical Properties of BaTiO3 Ceramics

BaTiO3 ceramics doped with various quantities of Nd2O3, Sm2O3, Gd2O3, Dy2O3 and Er2O3 were prepared respectively ( the adulterate concentrations were 0. 001,0. 002, 0. 003, 0.005, 0. 007 mol fraction) through a sol-gel method and their electrical properties were researched. It is found that each adulteration of Nd2O3, Sm2O3 Gd2O3,Dy2O3 and Er2O3 all can make the resistivity of BaTiO3 ceramics decline , especially Sm2O3 and Gd2O3. When the addition of Sm2O3 is 0. 001 mol, the resistivity is the smallest, declining from 4.0 × 1012 to 6.5 × 103 Ω different kind of rare earth exhibits different regularity. The grain resistance of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 exhibits a NTC effect, at the same time the grain boundary resistance has a PTC effect, and the grain boundary resistance is much larger than the grain resistance, so the PTC effects of BaTiO3 ceramics doped with Sm2O3 or Gd2O3 originate from the grain boundary. The additions of Nd2O3 , Gd2O3 or Er2O3 make the dielectric constant and the dielectric loss of BaTiO3 ceramics change evidently, especially Nd2O3. The dielectric constant is larger than that of pure BaTiO3 ceramics, on the other hand, the dielectric loss is much lower, which is useful in capacitor fields.     

ZnO-B_2O_3掺杂陶瓷的微观结构和微波介电性能

研究了ZnO-B_2O_3(ZB_2)对(Ca_(0.254)Li_(0.19)Sm_(0.14))TiO_3陶瓷的烧结行为和微波介电性能的影响。结果表明:ZnO-B_2O_3添加质量分数为3%时,试样的相对密度达到最大值;烧结温度从1 300℃降低到1 100℃时,试样的微波介电性能没有衰减。添加3%ZB_2(质量分数)的(Ca_(0.254)Li_(0.19)Sm_(0.14))TiO_3陶瓷在1 100℃烧结3 h呈现出较好的微波介电性能,介电常数ε_r=108.2,品质因数Q_f=6 545 GHz,共振频率温度系数τf=6.5×10~(-6)/℃,表明ZB_2是一种有效改善(Ca_(0.254)Li_(0.19)Sm_(0.14))TiO_3陶瓷致密性和微波介电性能的烧结助剂。     

Study on BaO-Sm2O3-TiO2 Microwave Dielectric Ceramics Doped with Bismuth and Zinc

BaO-Sm2O3-TiO2 microwave dielectric ceramics doped with Bi and Zn was studied. The experiment was based on BST microwave dielectric ceramics doped with Bi2O3, which is shown by Ba4(Sm1-yBiy)28/3Ti18O54. When y=0.15, ZnO was added and the effects of ZnO on this system were studied. The result shows that the dielectric characteristics of BST microwave dielectric ceramics are the most excellent when the content of ZnO is 3%, and the optimal sintering temperature is 1200 ℃.     

Dielectric Properties of CeO2 -Doped Ba( Zr, Ti)O3 Ceramics

The influence of additive amount of CeO2 on the properties of Ba(Ti, Zr)O3 (BTZ) capacitor ceramics prepared using conventional solid-state reaction method was investigated. The dielectric constant(ε) increases to a maximum when w( CeO2 ) is about 1.0% and then decreases again at higher doping concentration of CeO2. The dielectric constant gets a maximum while w ( CeO2 ) is about 1. 0%, and the dielectric loss is minimum while w ( CeO2 ) is0.5 %. CeO2 can decrease the curie temperature, widen the εr-T peak and decrease the absolute value of dielectric constant temperature coefficient. The influence mechanism of CeO2 additive on the properties of the BTZ ceramics was discussed. The results show that CeO2 additive influences the properties of BTZ ceramics by means of forming defect solid solution , shifting curie temperature peak effect, segregating in crystal boundary , and impeding grain growth.     

钛酸锶钡陶瓷的制备及介电性能

采用固相法和溶胶凝胶法制备钛酸锶钡(BaxSr1 xTiO3,BST)粉末,用X射线分析仪(XRD)和扫描电镜(SEM)分析2种方法制备的BST粉末的物相组成和显微形貌。固相法和溶胶凝胶法所得粉末制备的压坯分别在1 400℃和1 300℃烧结2 h得到BST陶瓷,用密度分析仪、扫描电镜(SEM)和阻抗分析仪对BST陶瓷的密度、断口显微形貌和介电性能进行分析,研究不同Ba/Sr比例和2种不同粉末颗粒尺寸对BST陶瓷介电性能的影响。结果表明:室温下,BaxSr1 xTiO3(x=0.5,0.6)为立方相,BaxSr1 xTiO3(x=0.7,0.8)为四方相;固相法粉末制备的BaxSr1 xTiO3(x=0.5,0.6,0.7,0.8)陶瓷的密度、颗粒尺寸和介电常数峰值均随Ba含量的增加而增加,居里温度随Ba含量的增加呈线性增加,线性拟合得到Tc=221.6+354x,BST陶瓷的介电常数随频率的增加而降低;与固相法粉末制备的BST陶瓷相比,溶胶凝胶法粉末制备的BaxSr1 xTiO3(x=0.5,0.6)陶瓷密度较高,但同时出现介电峰弥散,介电常数和介电损耗较低。     

氧化钆对钛酸钡陶瓷结构和介电性能的影响

采用固相法制备得到了掺杂 1% (mol) Gd2 O3的钛酸钡陶瓷 ,并通过 X射线衍射分析和扫描电镜对其结构进行了表征。对其介电常数、介电损耗和室温电阻率进行了测定 ,结果表明 Gd2 O3掺杂 Ba Ti O3陶瓷的介电常数明显增加 ,介电损耗也有所升高 ,室温电阻率明显降低     

Microwave dielectric properties of Ba6-3xLa8+2x(Ti1-zZrz)18O54(x=2/3)ceramics

Zr substitution for Ti was investigated to modify the dielectric properties of Ba6-3xLa8+2xTi18O54(x=2/3) ceramics.A single-phase solid solution with tungstenbronze-like structure was formed in the range of 0     

Deposition and Characterization of (Ba, Sr)RuO3 Oxide Electrode Using TMHD-Based Single Cocktail Source

(Ba, Sr)RuO3 has been paid an attention as a promising electrode for (Ba, Sr)TiO3 dielectric material due to its similarity in structure and chemical composition with BST. In this study, (Ba, Sr)RuO3 conductive oxide film was deposited on a 4 inch p-type Si wafer by metal organic chemical vapor deposition (MOCVD) using single cocktail source for the practical device application. Ba(TMHD)2, Sr(TMHD)2, Ru(TMHD)3 precursors and solvent [1-EtylePiPerdine (C7H15 N) ] as starting materials were mixed together for single cocktail source. A liquid delivery system (LDS) and a vaporization cell were utilized for the delivery and vaporization of single cocktail source, respectively. The source feeding rate was controlled by a liquid mass flow controller (LMFC). Deposition parameters, such as the oxygen flow and the source flow rate,were sensitive to phase formation, resistivity and the composition ratio of (Ba, Sr)RuO3 films. Highly (110)-textured (Ba,Sr)RuO3 film was obtained vhen the Ar/O2 ratio was 200/140 sccm at a source flow rate of 0.05 sccm. The process window of stoichiometric composition of BSR film was observed with varying the source flow rate from 0.05 sccm to 0.1 sccm.     

Mg~（2＋）,Ca~（2＋）,Ba~（2＋）离子部分取代对SrAl_2O_4：Eu~（2＋）,Dy~（3＋）晶体结构和发光性能的影响

采用高温固相反应法制备了Sr0.9M0.1Al2O4：Eu2＋,Dy3＋（M=Mg,Ca,Ba）长余辉发光材料,并对其晶体结构、光谱性质、余辉特性进行了分析.X射线衍射测试结果表明,Mg2＋,Ca2＋,Ba2＋离子部分取代SrAl2O4基质中的Sr后,基质晶体结构并没有发生改变.光谱测试结果表明,Mg2＋,Ca2＋,Ba2＋取代后发光材料的激发光谱都是一个从250~450 nm范围内的宽激发带,在266nm,320nm,360nm,416 nm处各有一个激发峰.发射光谱中Mg2＋和Ba2＋的取代使波长出现蓝移,而Ca2＋的取代使波长出现红移.余辉测试结果表明,Ca2＋取代后的余辉时间长于Mg2＋和Ba2＋的取代.     

Properties of La2O3-Doped PNSZT Piezoelectric Ceramics Having Tetragonal and Rhombohedral Coexistent Phases

The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohedral coexistent phases, was studied. A series of piezoelectric ceramics with good properties was obtained, having dielectric constants(ε=1500～2500), plane electromechanical coupling factor(Kp=0.45～0.65), mechanical quality factor(Qm=500～1600). These materials are used for making ultrasonic sensor and filter, and marine acoustic launching and receiving device, and so on. It has been explored that the influence of composition on the lattice constant and phase composition of La2O3-doped PNSZT piezoelectric ceramics by XRD(X-ray diffraction). The character of dielectric constant changing of La2O3-doped PNSZT piezoelectric ceramics before polarization and after polarization was studied. The affecting mechanism about composition on the electric machine properties of phase coexistent La2O3-doped PNSZT piezoelectric ceramics was analyzed and discussed.     

Effects of rare earth oxides on dielectric properties of Y2Ti2O7 series ceramics

A series of Y2Ti2O7 microwave dielectric ceramics were synthesized by conventional solid-state method. The effects of rare earth oxide (La2O3, CeO2, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Dy2O3) and Nd2O3 doping content on the microstructure and dielectric properties of Y2Ti2O7 ceramics were investigated. The experimental results showed that the rare earth ions were considered to dissolve in Y-sites of the pyrochlore structure, different rare earth oxides and concentration had different influences on Y2Ti2O7 cerami...     

CuTa_2O_6掺杂Ba(Zn_(1/3)Ta_(2/3))O_3基微波陶瓷烧结动力学及微波性能

结合烧结动力学模型和微观形貌观察,研究未掺杂和掺杂CuTa_2O_6的Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷在1 270~1 520℃温度范围内的致密化过程和烧结动力学机理。结果表明:在1 150℃以上烧结,随温度升高,Ba(Zn_(1/3)Ta_(2/3))O_3的烧结机制从体积扩散向晶界扩散转变。掺杂0.25%CuTa_2O_6可显著加快Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷的烧结致密化过程,在显著降低烧结温度的同时,可大幅缩短烧结时间并有效地促进B位的有序化。掺杂Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷在1370℃烧结12h即可获得96%的相对密度,在1 370℃烧结12 h后的介电常数(εr)和品质因数(Q·f)分别约为29.4和985 35;相比较,未掺杂Ba(Zn_(1/3)Ta_(2/3))O_3在1 520℃烧结12 h的εr和Q·f分别只有27.4和68 147。掺杂Ba(Zn_(1/3)Ta_(2/3))O_3陶瓷经1 520℃烧结48 h的εr和Q·f分别约为28.2和103 131。     

Photoluminescence of Dy~(3 ) Ions in Ba_3La(BO_3)_3

Dy3 isanimportantactivator .Ithasbeenexten sivelyappliedinmanyluminescentmaterials .Inre centyears ,someresearchershavestudiedthespec trumcharacteristicsofluminescentmaterialsdopedDy3 [1～ 6 ] andhaveobtainedsomemeaningfulre sults .InordertodevelopnewfluorescentmaterialsanddiscussthephotoluminescentruleofDy3 inthecomplexborate ,thispaperstudiesthephotolumines centcharacteristicsofDy3 inBa3La(BO3) 3host ,anddiscussestheinfluenceofthecharge to radiusratio(z/r)ofrareearthionRE3 andthecon…     

组分影响(Na1/2Bi1/2)TiO3介电性能的研究

采用正交设计试验法研究了配方对钛酸铋钠(Na1/2Bi1/2)TiO3(BNT)铁电陶瓷介电性能的影响,得到了影响BNT陶瓷介电性能的主次因素以及各因素水平影响其性能的趋势,进而得到了综合性能佳的BNT陶瓷.探讨了各组分对BNT陶瓷介电性能影响的机理,为BNT陶瓷材料的改性研究提供了依据.