硅基(Pb,La)(Zr,Ti)O_3反铁电厚膜的制备及介电性能

采用溶胶–凝胶工艺制备了具有高度(100)择优取向的(Pb,La)(Zr,Ti)O3反铁电厚膜(厚约2.2μm)。研究了该反铁电厚膜在不同温度下的电场诱导相变效应和不同电场强度下的温度诱导相变效应。结果表明:(Pb,La)(Zr,Ti)O3反铁电厚膜在室温下处于反铁电态;随着温度升高,厚膜的相变开关电场强度逐渐降低,反铁电态越来越不稳定,当温度高于132℃且电场强度为0 kV/cm时,厚膜处于顺电态;随着外加电场强度的增大,厚膜的AFE(反铁电态)-FE(铁电态)相变温度向低温方向漂移,当电场强度大于164 kV/cm时,厚膜在室温下已处于铁电态。     

多步退火对(Pb,La)(Zr,Ti)O_3反铁电厚膜的影响

采用溶胶-凝胶技术,在Pt(111)/Ti/SiO2/Si(100)基底上制备Pb0.97La0.02(Zr0.95Ti0.05)O3反铁电厚膜材料,研究了单步和多步退火工艺对反铁电厚膜结构及电学性能的影响。结果表明:与传统的单步退火方式相比,多步退火工艺制备的反铁电厚膜材料晶粒尺寸较大,结构致密性好,室温下反铁电态更稳定,具有良好的择优取向度(100)、较高的介电常数(达529)和饱和极化强度(达42μC/cm2)。其反铁电-铁电和铁电-反铁电的相变电场强度分别为198和89 kV/cm,反铁电-铁电相变电流密度达2×10-5 A/cm2,多次退火工艺可提高反铁电厚膜的成膜质量。     

PLT晶种层对PLZT薄膜介电性能的影响

采用sol-gel工艺,以钛酸铅镧(PLT)作为晶种层,在Pt/TiO2/Si基板上,制备了锆钛酸铅镧(PLZT)薄膜。研究了有晶种层的PLZT薄膜的结晶温度及介电性能。结果表明:引入PLT晶种层的PLZT薄膜,在600℃热处理可得到良好的钙钛矿结构,比无晶种层薄膜降低了约100℃;其相对介电常数为1177(1 kHz),提高约60%,介质损耗为0.10～0.13,降低幅度最高可达40%～50%。     

氧化铈对堇青石基微晶玻璃介电性能的影响

采用X-射线衍射(XRD)、扫描电镜(SEM)等手段研究了CeO2在堇青石基玻璃烧结中的作用及其添加量对微晶玻璃的烧结和性能的影响。结果表明,CeO2的加入可有效促进微晶玻璃的烧结致密化;随着CeO2加入量的增加,烧结样品的介电常数呈现先增加后降低的趋势,且与密度变化曲线相似;当CeO2添加量达4%(质量分数)时样品的介质损耗因子最低(≈0.2%)。     

烧结工艺对纳米SrTiO3陶瓷介电性能的影响

采用sol-gel方法制备SrTiO3陶瓷粉体,利用TG-DTA分析SrTiO3干凝胶粉的分解、化合反应,初步确定了SrTiO3陶瓷预烧和烧结温度,采用SEM研究了SrTiO3陶瓷的内部结构,重点探讨了不同烧结制度对SrTiO3陶瓷介电性能的影响。研究表明,当采用在空气气氛下以5℃／min的升温速率直接升温至1000℃,保温0．5h,再降温至750℃保温0．5h后随炉冷却的烧结工艺,SrTiO3陶瓷纯度高,致密性好,晶粒粒径小于100nm,且具有良好的介电性能,低频下相对介电常数高达3000左右。     

BNN对BZN系统结构和介电性能的影响

研究了Ba（Ni1／3Nb2／3）O3（BNN）对Ba（Zn1／3Nb2/3）O3（BZN）系统结构和介电性能的影响。系统的主晶相为立方钙钛矿结构的BZNN，并有少量第二相如Ba5Nb4O15，BaNb2O6等。实验表明，引入适量的BNN可以调整BZN的温度系数，且能有效改善其介电性能，当BNN摩尔分数为0．7时，于1450℃，1500℃烧结时性能最好。系统在较高温度下（1550℃）烧结时形成富Nb液相区。     

ZnO、CeO2对BNCT介电性能的影响

为了获得高温稳定的电容材料,研究了ZnO、CeO2掺杂对Mn改性(Bi0.5Na0.5)0.88Ca0.12TiO3陶瓷材料介电性能的影响,并借助于XRD和SEM进行了微观分析.研究发现:随着ZnO掺杂量的增加,介电常数先增加后减小;容温变化率(△C/C25℃)曲线高温段改善;介质损耗在100℃以上的高温段先减小后又增加.XRD表明ZnO、CeO2的添加都引入了第二相;SEM显示添加质量分数为2%的ZnO能抑制异常晶粒,使晶粒均匀致密.在ZnO掺杂基础上添加CeO2,进一步改善了容温特性.当ω(CeO2)=1.2%～2.4%时,在-55～250℃范围内△C/C25℃≤±8%.     

MPCVD金刚石膜的品质对其在K-Ka波段微波介电性能的影响

针对MPCVD金刚石膜K-Ka波段(18～40 GHz)微波电子器件领域的应用需求,以及探索金刚石膜介电性能与品质之间的关系的需要,制备了5个金刚石膜样品,并建立了一套K波段分体圆柱谐振腔微波介电性能测试装置。使用Raman光谱表征金刚石膜质量,采用K波段分体圆柱谐振腔测量金刚石膜的介电性能,并与Ka波段的结果进行比较。结果表明,不同品质的样品介电损耗在3.8×10~(-5)～76.8×10~(-5)范围内,且介电损耗与Raman半峰宽密切相关。同时,高品质金刚石膜K波段介电损耗高于Ka波段,而低品质的则呈现相反的结果。这是由于高品质金刚石膜介电损耗主要由导电性引起,而低品质金刚石膜内较高的缺陷密度导致单声子声学振动吸收和瑞利散射较大。     

Sb2O3对钛酸锶钡基陶瓷介电性能及结构的影响

采用传统固相法制备Sb2O3掺杂(Ba0 612Sr0.38Y0.008)TiO3系电容器介质陶瓷,研究了不同质量分数的Sb2O3在各烧结温度下对体系介电性能及微观结构的影响.当Sb2O3的掺杂量为0.4%时,试样在1 320℃下保温2 h,体系的室温相对介电常数可达3 000,介电损耗仅为2×103,居里温度向负温方向移动至-24℃.研究表明:两性氧化物Sb2O3通过占据钙钛矿晶格A位,显著降低了体系相对介电常数及介质损耗,起到了良好的移峰及展宽效应;与此同时,Sb2O3改善了体系微观形貌,有效降低晶粒尺寸.     

高场强下铝阳极氧化膜中相关元素的分布及其介电性能

利用俄歇电子能谱仪（ＡＥＳ）分析了高场强下不同条件形成的阳极氧化膜中相关元素的分布,分析表明膜中不同程度存在Ｂ、Ｃ、Ｐ等相关元素。测试其相应的介电性能,表明氧铝比Ｒ（Ｏ∶Ａｌ）接近于１．５时其介电性能较好。     

Influence of La-Mn-AI Co-Doping on Dielectric Properties and Structure of BST Thick Film

A new sol-gel process is applied to fabricate the BST （BaxSr1-xTiO3） sol and nano-powder of La-Mn-Al co-doping with Ba/Sr ratio 65/35, and the BST thick film is prepared in the Pt/Ti/SiO2/Si substrate. The powder and thick film are characterized by X-ray diffraction and transmission electron microscope. The influence of La-Mn-Al co-doping on the dielectric properties and micro-structure of BST thick film is analyzed. The results show that the La, Mn, and Al ions can take an obvious restraint on the growth of BaSrTiO3 grains. The polycrystalline particles come into being during the crystallization of thick film, which may improve the uniformity and compactness of thick film. The influence of unequal-valence and doping amount on the leakage current, dielectric loss, and dielectric property are mainly discussed. The dielectric constant and dielectric loss of thick film are 1200 and 0.03, respectively, in the case of 1mol% La doping, 2mol% Mn doping, and 1mol% Al doping.     

Influence of La-Mn-Al Co-Doping on Dielectric Properties and Structure of BST Thick Film

A new sol-gel process is applied to fabricate the BST (BaxSr1(xTiO3) sol and nano-powder of La-Mn-Al co-doping with Ba/Sr ratio 65/35, and the BST thick film is prepared in the Pt/Ti/SiO2/Si substrate. The powder and thick film are characterized by X-ray diffraction and transmission electron microscope. The influence of La-Mn-Al co-doping on the dielectric properties and micro-structure of BST thick film is analyzed. The results show that the La, Mn, and Al ions can take an obvious restraint on the growth of BaSrTiO3 grains. The polycrystalline particles come into being during the crystallization of thick film, which may improve the uniformity and compactness of thick film. The influence of unequal-valence and doping amount on the leakage current, dielectric loss, and dielectric property are mainly discussed. The dielectric constant and dielectric loss of thick film are 1200 and 0.03, respectively, in the case of 1mol% La doping, 2mol% Mn doping, and 1mol% Al doping.     

Al掺杂ZnO厚膜的sol-gel法制备及其气敏性能研究

以硝酸锌、硝酸铝和氢氧化钠为原料,采用sol-gel法制备铝掺杂的纳米氧化锌厚膜(样品),并利用XRD和SEM对其微观结构进行了表征。研究了铝掺杂量和退火温度对ZnO厚膜的气敏性能的影响。结果表明:700℃退火、掺w(Al)为2.9%的样品对体积分数为4.0×10–1的丙酮有很好的选择性,最大灵敏度达到7 779左右,最佳工作温度约为162℃,响应、恢复时间均为1 s,最后讨论了铝掺杂纳米氧化锌的气敏机理。     

B2O3-Li2O掺杂对丝网印刷Bao.6Sr0.4TiO3厚膜微观结构及介电特性的影响

采用丝网印刷工艺并通过有效掺杂B2O3-Li2O制备出了一致性和可重复性良好的Ba0.6Sr0.4TiO3(BST)厚膜.系统研究了B2O3-Li2O掺杂对BST厚膜的低温烧结特性、微观结构、相构成及介电性能的影响.结果表明:随着B2O3-Li2CO3含量的增加,BST厚膜的烧结温度逐渐降低,晶粒尺寸和介电常数显著变小...     

Pb_(0.88)La_(0.08)(Zr_xTi_(1–x))O_3铁电厚膜介电与储能性能研究

采用溶胶-凝胶法在La Ni O3/Si(100)底电极上成功制备了厚度为1μm的Pb0.88La0.08(Zrx Ti1–x)O3(PLZT,x=0.30,0.55,0.80)铁电厚膜。研究了不同Zr/Ti比对PLZT铁电厚膜的介电与储能性能的影响。结果表明,随着PLZT中Zr含量的增加,厚膜材料的储能密度与储能效率均增大,Pb0.88La0.08(Zr0.8Ti0.2)O3厚膜在1 400×103V/cm的储能密度为23.8 J/cm3,储能效率为60%。     

Enhanced dielectric properties of Zr−Sn−Ti oxynitride thin films

Zr_0.26Sn_0.23Ti_0.51O_xO_y (ZSTON) and Zr_0.26Sn_0.23Ti_0.51O_2σ (ZSTO) films have been prepared on Pt coated silicon substrates by pulsed laser deposition technique using a Zr−Sn−Ti oxide target at a substrate temperature of 650°C in N₂ and O₂ ambient, respectively. TEM observation showed that both kinds of films are amorphous. XPS analysis showed that the N/O ratio in ZSTON is 0.08/0.92. With the help of a comparative study of the dielectric properties of ZSTON and ZSTO films, it has been found that incorporation of nitrogen can increase the dielectric coefficient and decrease the dielectric loss of the multicomponent oxide films remarkably. Optical transmittance measurements showed that incorporation of nitrogen can slightly decrease the width of the bandgap and increase the refractive index of the films. It is proposed that amorphous Zr−Sn−Ti oxynitride stable at 650°C is a potential dielectric material for DRAM applications.     

ZnO掺杂TiO2厚膜的sol-gel法制备及气敏特性研究

利用钛酸丁酯与无水乙醇的水解反应制备了纳米TiO2厚膜,并对其进行了不同含量的ZnO掺杂和不同温度的退火.通过XRD和SEM对所制备的ZnO-TiO2纳米粉的物相结构和表面微观形貌进行了表征,利用气敏元件测试系统对用其制备的气敏元件的气敏特性进行了检测,研究了ZnO的掺杂量和退火温度对TiO2厚膜气敏性能的影响,并对T...