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掺杂球形Li1+xV3O8的制备及其电化学性能研究 总被引:6,自引:0,他引:6
采用溶胶-凝胶和喷雾干燥相结合的方法合成了掺杂Mn和Co的球形Li1 xV3O8材料.选取Mn和Co作为掺杂元素,并且通过实验确定掺杂的量以1%为最佳.考察了不同热处理温度对掺杂Li1 xV3O8晶体结构与电化学性能的影响.对掺杂后的样品进行了XRD、SEM及电化学性能测试研究.结果表明,掺杂对样品的形貌和结构没有产生影响,350℃热处理温度下制备的掺杂Li1 xV3O8样品在常温下的循环性能有了较大的改善,其中掺CO后的样品性能改善最为显著. 相似文献
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S-Co复合掺杂LiMn2O4的合成与性能 总被引:2,自引:0,他引:2
为了扩大锂离子电池正极材料LixMn2O4的工作电压范围,在保证良好循环性能的基础上提高材料的容量,本文对S-Co复合掺杂LiMn2O4的合成工艺和电化学性能进行了研究.溶胶-凝胶法合成的各试样均为纯的立方尖晶石相,且结晶状态良好.S—Co复合掺杂综合了S掺杂效应和Co掺杂效应,改善了LiMn2O4的电化学性能,在2.4—4.3V充放电压范围内,初始容量较高,达到170mAh/g,30次循环后容量不但没有衰减而且有一定增加. 相似文献
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Yb2O3的掺杂方式对Ba(Ti1-y)Zry)O3陶瓷介电性能的影响 总被引:2,自引:0,他引:2
在Ba(Ti1-yZry)O3中,Yb2O3的不同掺杂方式引起了材料性能的显著变化,采用Ba(Ti1-yZry)O3合成后Yb2O3的适量掺杂,陶瓷介温峰明显地移动,介电常数大幅度提高,获得了室温介电常数>25000,1250℃左右烧成,符合Y5V标准的高介材料,合成后掺杂的Yb2O3,使材料介电常数提高,可能与施主掺杂引入的局域化电子有关,合成前掺杂Yb2O3的样品,介电常数较低,移峰效率偏小,可能是Yb的Ti位受主取代使施主引入的局域化电子得到补偿的结果。 相似文献
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用固相法制备出了Eu^2+,Dy^3+共掺杂Sr4Al7O25:Eu^2+,Dy^3+、SrAl2O4:Eu^2+,Dy^3+长余辉发光材料。研究了硼酸含量对其制备过程及发光性能的影响。用XRD对所合成材料进行物相分析,用荧光光谱仪记录其发射光谱,并在暗室里拍摄紫外激发下的发光照片。结果表明:随着硼酸加入量的不同,Eu^2+、Dy^3+共掺杂铝酸锶的发光效果、形貌特征均不同。在某一范围内,随着硼酸添加量的增加,材料的发光性能、发光亮度均有所提高,烧结温度有所降低。 相似文献
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采用传统陶瓷制备方法,制备出La2O3和CeO2掺杂的(Bi1/2Na1/2)0.94Ba0.06TiO3无铅压电陶瓷,研究了微量稀土元素La,Ce对(Bi1/2Na1/2)0.94Ba0.06TiO3无铅压电陶瓷微观结构、介电与压电性能的影响。XRD分析表明,La2O3和CeO2的掺杂量在0.1%~0.8%C质量分数)范围内都能形成纯钙钛矿(ABO3)型固溶体。测试了不同组成陶瓷的介电、压电性能,陶瓷材料的介电常数.温度曲线显示La2O3掺杂的陶瓷在升温过程中存在两个介电常数温度峰,而CeO2掺杂的陶瓷的低温介电常数温度峰不明显;在La2O3和CeO2掺杂量为0.3%时陶瓷的压电常数d33分别为156pC/N和160pC/N,为所研究组成中的最大值,平面机电耦合系数Kp最大值出现在La2O3和CeO2掺杂量为0.1%时,分别为0.32,0.31。 相似文献
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硼在Eu2+,Dy3+共激活srAl2 O4发光材料中作用的研究进展 总被引:1,自引:0,他引:1
概括了SrAl2O4:Eu2 ,Dy3 在加硼和不加硼条件下的合成和性能对比,阐述了硼掺杂对Eu2 ,Dy3 共激活SrAl2O4的影响及作用:一方面,硼作为助熔剂可以降低烧成温度促使单斜SrAl2O4相的形成;另一方面,硼掺杂能促进Eu3 的还原以及Eu离子在SrAl2O4体系中的扩散和取代并促使发光中心的形成和稳定,从而使得材料的发光性能有所改善.此外,硼掺杂也引入了一些问题,如粉体烧结等,也对此做了概括并提出了展望. 相似文献
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以CoCl2·6H2O、ZnCl2、AlCl3和CrCl3·6H2O为原料,采用水热法合成了CoAl2O4(AB2O4)尖晶石型纳米钴蓝色料.采用色度分析、X射线衍射(XRD)、透射电镜(TEM)以及高分辨透射电镜(HRTEM)等研究了A位掺杂Zn2+和B位掺杂Cr3+时不同掺杂量以及不同水热合成温度对样品呈色、晶相组成及CoAl2O4尖晶石的晶粒大小、发育程度和晶面间距的影响.结果表明,掺杂Zn2+、Cr3+所得固溶体型钴蓝色料晶粒发育均不完整,颗粒较于相同水热条件下获得的未掺杂样品更细小.A位掺杂Zn2+可降低CoAl2O4色料的合成温度,在230℃便能制得呈色较佳的Co0.95Zn0.05Al2O4钴蓝色料.随着Zn2+掺杂量的增加,合成产物由蓝色转为绿色,且呈色逐渐变浅.B位Cr3+掺杂则随着掺杂量的增加,产物从蓝色逐步转为绿色,但呈色逐渐变深.就两者相比较,A位掺杂Zn2+更有利于色料明度值的提高而呈色鲜亮. 相似文献
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Liquid-phase sintered Si3N4 doped with Yb2O3 as a sintering aid was characterized by both transmission electron microscopy and extended X-ray absorption fine structure (EXAFS) measurements. Structural information about the secondary phases was obtained with an emphasis being placed on the evaluation of EXAFS data. Two Si3N4 samples were processed which contained either 5 vol% or 10 vol% Yb2O3 as sintering additive. After sintering, only an amorphous secondary phase was observed in the material doped with 5 vol% Yb2O3. The material with the higher Yb2O3 volume fraction underwent a further heat treatment after the densification, in order to crystallize pockets of the secondary phase. This heat treatment resulted in the formation of Yb2Si2O7 at multi-grain junctions, with however, amorphous phases remaining along the grain and phase boundaries. The EXAFS data obtained from the two doped Si3N4 materials were compared with reference spectra obtained on pure Yb2O3 and synthetic Yb2Si2O7. No residual Yb2O3 was determined in the doped Si3N4 materials, independent of the Yb2O3 volume fraction. Compared to synthetic Yb2Si2O7, the secondary phase formed in the 10 vol% Yb2O3 containing material showed only subtle changes in the EXAFS data. A clear distinction between purely amorphous and a combination of crystalline plus amorphous Yb secondary phases was possible, when both doped Si3N4 materials were compared. However, no distinction between the glass phase present at triple junctions and the amorphous residue along grain/phase boundaries was feasible, since a full numerical data evaluation could not be performed. 相似文献
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Ba1-xSrxTiO3 ceramics, doped with B2O3-Li2O glasses have been fabricated via a traditional ceramic process at a low sintering temperature of 900 ℃ using liquid-phase sintering aids. The microstructures and di- electric properties of B2O3-Li2O glasses doped Ba1-xSrxTiO3 ceramics have been investigated systemat- ically. The temperature dependence dielectric constant and loss reveals that B2O3-Li2O glasses doped Ba1-xSrxTiO3 ceramics have di?usion phase transformation characteristics. For 5 wt% B2O3-Li2O glasses doped Ba0.55Sr0.45TiO3 composites, the tunability is 15.4% under a dc-applied electric field of 30 kV/cm at 10 kHz; the dielectric loss can be controlled about 0.0025; and the Q value is 286. These composite ceramics sintered at low temperature with suitable dielectric constant, low dielectric loss, relatively high tunability and high Q value are promising candidates for multilayer low-temperature co-fired ceramics (LTCC) and potential microwave tunable devices applications. 相似文献
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SrTiO3独石化晶界层电容器研究 总被引:2,自引:0,他引:2
本文研究了低温烧结SrTiO3晶界层瓷料系统中Bi2O3、Li2O、SiO2等掺杂剂对瓷料半导化及烧结特性的作用与影响,讨论了将这种瓷料应用于常规多层陶瓷电容器制作技术的工艺特点和技术关键。实验表明,利用晶界偏析技术制造SrTiO3独石化晶界层电容器是一条可行性好的技术路线。 相似文献
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An alpha-Al2O3 and MgAl2O3 spinel phase doped alpha-Al2O3 nanopowders were fabricated by the thermal decomposition and synthetic of ammonium aluminum carbonate hydroxide (AACH). Crystallite size of 5 to 8 nm were fabricated when reaction temperature of AACH was low, 8 degrees C, and the highest [NH4+][AlO(OH)2-][HCO3] ionic concentration of pH 10 from the ammonium hydrogen carbonate (AHC) aqueous solution. The phase transformation of amorphous-s, theta-, alpha-Al2O3, MgAl2O3 spinel phases was examined at each temperature according to the amount of Mg(NO3)2 x 6H2O and AACH. A time-temperature-transformation (TTT) diagram for thermal decomposition in air was determined. Homogeneous, spherical alpha-Al2O3 nanopowders with a particle size of 60 nm were obtained by firing the crystallites, which had been synthesized from AACH at pH 10 and 8 degrees C, at 1050 degrees C for 6 h in air. 相似文献
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采用普通陶瓷工艺制备了Gd掺杂的Co2Z型平面六角铁氧体3(Ba0.5Sr0.5O).2CoO.0.05Gd2O3.10.8Fe2O3,对其微结构和高频性能进行了研究。结果表明,少量掺杂Gd的Co2Z型铁氧体仍具有单相的Z型平面六角结构,其磁导率实部μ′明显提高,可达到13,而截止频率仍大于1GHz,具有较好的高频性能。随着烧结温度的提高,材料的磁导率实部μ′增大,但截止频率下降。少量Gd的掺杂对Co2Z型铁氧体的复介电常数值没有明显影响,但材料的铁电共振峰向高频区移动。 相似文献
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稀土氧化物掺杂对SnO2基气体传感器材料性能的影响 总被引:8,自引:0,他引:8
采用化学共沉淀法制备Y2O3、ZrO2,Er2O3和Sb2O2基气体传感器。结果表明掺杂后的材料经煅烧后,平均晶粒尺寸均小于30nm,比未经掺杂的材料小,中掺杂体系不同成分材料制备成厚膜传感器,进行了对CO气体敏感度性能测试,发现掺杂稀土氧化物的气体敏感度较纯SnO2厚膜传感器高。其中掺杂Er2O3材料性能最好。 相似文献