氧化锌铝(ZAO)陶瓷靶材制备及其薄膜性能

溶胶-凝胶方法制备的ZnO和Al2O3混合粉末经冷压预成型加真空低压烧结,制备了高致密度(相对密度99%)、低成本的ZAO陶瓷靶材.研究了ZAO靶材与无氧铜的粘接性能.用中频交流磁控溅射ZAO靶材的工艺制备了ZAO薄膜.利用SEM和XRD分析测试了陶瓷靶材断口形貌以及靶材和薄膜的结构.试验结果表明制得的ZAO靶材具有良好的粘接性和溅射性能,内部组织致密,靶材中有明显的ZnAl2O4相.在优化沉积工艺条件下,制备的ZAO薄膜方块电阻为35 Ω,电阻率可达3.84×10-4 Ω·cm,可见光透过率(λ=550 nm)可达91.1%.沉积态的ZAO薄膜具有很好的结晶性,并呈现(002)择优取向.ZAO薄膜有明显的紫外吸收限,带隙Eg约为3.76 eV.ZAO靶材的工业化磁控镀膜试验也取得了较好的结果.     

Structural,Transport and Optical Properties of Boron-doped Zinc Oxide Nanocrystalline

The paper has reported the structural,transport and optical properties of boron doped zinc oxide(ZnO:B) thin films grown on glass substrate by sol-gel spin coating process.It is observed from the analysis of the X-ray diffraction(XRD) results that the crystalline quality of the films is improved with increasing B concentration.A crystallite size of ～17 nm is obtained for B doped films.A minimum resistivity of 7.9×10-4 Ω.cm is obtained at 0.6 at.% of B concentration in the ZnO:B films.Ionized and intragrain cluster scattering are found to dominate the scattering mechanism in ZnO:B films.Optical interference pattern in transmittance spectra shows good homogeneity with a transparency of ～88% in the visible region.The band gap of the films is increased from 3.24 to 3.35 eV with increasing B concentration.Band gap widening is analyzed in terms of Burstein-Moss shift.The origin of the broad band photoluminescence(PL) spectra is explained in terms of the intragrain cluster scattering.     

Far Infrared Optical Properties of Bulk Wurtzite Zinc Oxide Semiconductor

Polarized far infrared (FIR) reffectance technique was applied to study the optical properties of a bulk wurtzite zinc oxide (ZnO) single crystal. Room temperature polarized FIR reffectance spectra were taken at various angles of incidence, from 20 to 70. The theoretical polarized FIR reffectance spectra were simulated based on the anisotropic dielectric function model. Good agreement was achieved between the experimental and the theoretical FIR reffectance spectra. Through this work, a complete set of reststrahlen parameters of a bulk wurtzite ZnO at the Brillouin zone centre was obtained. Additionally, other FIR optical properties such as the real and the imaginary parts of the complex dielectric function, real and imaginary parts of the refractive index, the absorption coeficient and the reciprocal of the absorption coeficient were also obtained by using numerical calculation.     

高能粒子辐照对零膨胀微晶玻璃光学性质和面形光学稳定性的影响

研究了高能电子，高能质子对ＶＯ２微晶玻璃辐照前后光性质和面形光学稳定性的影响，研究结果表明，高能电子辐照能引起微晶玻璃面形明显变化，且使ＶＯ２微晶玻璃强烈着色。高能质子辐照没引起面形明显变化，高能质子辐照对反射光谱特性没有影响。     

氧化锌压敏电阻微波烧结行为的研究

采用微波和传统烧结工艺制备了ZnO压敏电阻,比较了微波和传统烧结ZnO压敏电阻的相组成、表面微观结构和电性能,探讨了烧结温度和保温时间对微波烧结样品的致密化和电性能的影响.与传统工艺相比,微波烧结工艺明显改善了ZnO压敏电阻的致密化行为,缩短了烧结周期,改善了电性能.优化的微波烧结样品的压敏电压U1mA为521.8V,非线性系数α是61.4,漏电流IL为1.25×10-6A,残压比Kr为1.45,通流量Im达11600A,均达到或超过了传统工艺水平.微波烧结样品的通流量Im更是比传统烧结样品高约50%.     

烧结助剂及Mo含量对AlN-Mo复合陶瓷热导率的影响

以CaF2、CaCO3为烧结助剂,采用热压烧结法制备了AlN-Mo复合材料.利用XRD和SEM分析了AlN-Mo复合陶瓷的相组成及其微观形貌,并讨论了烧结助剂和Mo含量对该材料热导率的影响.结果表明,CaF2和CaCO3烧结助剂的添加量在1％～3％(质量分数)范围内,AlN-Mo复合材料的热导率随着CaF2含量的增加而升高,随着CaCO3含量的增加先升高后降低.在烧结助制的种类和含量一定时,含20％(体积分数)Mo的AlN-Mo复合陶瓷的热导率高于含18％(体积分数)Mo的AlN-Mo复合陶瓷的热导率.     

Fundamental Optical Spectra of Zinc Oxide

The complete set of fundamental optical spectra for zinc oxide at 100 K is calculated in the range 0–25 eV using experimental reflection spectra and Kramers–Kronig relations. The dielectric permittivity and electron energy loss spectra are decomposed into transverse and longitudinal elementary components using combined Argand diagrams, and the principal parameters of the components are evaluated. The key features of the optical spectra and transitions are compared with the results of ab initio band structure calculations.     

细晶氧化铝陶瓷的烧结和力学性能研究

以30 nm、150 nm、1μm的Al2O3粉为原材料,用两步法和常规烧结法得到了一系列晶粒尺寸不同的致密的氧化铝陶瓷,并对不同晶粒尺寸的Al2O3陶瓷的微观结构、密度和抗弯强度等方面进行研究.结果表明:用两步法烧结得到的Al2O3陶瓷的晶粒尺寸小于用常规烧结法得到的,而且,随着晶粒尺寸减小,晶粒形状由板状变成了球形,抗弯强度逐渐增加.     

Optical and field emission properties of Zinc Oxide nanostructures

Zinc Oxide (ZnO) nano-pikes were produced by oxidative evaporation and condensation of Zn powders. The crystalline structure and optical properties of the ZnO nanostructures (ZnONs) greatly depend on the deposition position of the ZnONs. TEM and XRD indicated that the ZnONs close to the reactor center, ZnON-A, has better crystalline structure than the ZnONs away from the center, ZnON-B. ZnON-A showed the PL and Raman spectra characteristic of perfect ZnO crystals, whereas ZnON-B produced very strong green emission band at 500 nm in the photoluminescence (PL) spectrum and very strong Raman scattering peak at 560 cm(-1), both related to the oxygen deficiency due to insufficient oxidation of zinc vapor. ZnON-B exhibited better field emission properties with higher emission current density and lower turn-on field than ZnON-A.     

Microstructure and Optical Properties of Yttrium-doped Zinc Oxide(YZO) Nanobolts Synthesized by Hydrothermal Method

In this work,yttrium-doped zinc oxide(YZO) nanopowder was synthesized via hydrothermal precipitationmethod. The microstructure and optical properties of yttrium-doped zinc oxide nanopowder were characterized,which confirmed the well-crystalline wurtzite hexagonal phase of Zn O. The yttriumdoped zinc oxide nanopowder grains formed the nanobolts of ~400 nm in length and ~900 nm in width.High resolution-transmission electron microscopy(HR-TEM) of the nanobolts revealed uniform lattice fringes and no visible faults and/or distortions. X-ray photoelectron spectroscopy(XPS) analysis confirmed the presence of yttrium in the zinc oxide lattice,proving the contribution of yttrium on the microstructural and optical properties of the material. A strong ultra violet(UV) emission peak of the YZO exhibited a red shift compared to pure zinc oxide,which was ascribed to the defects and the formation of a shallow energy level caused by the incorporation of yttrium.     

共沉淀包膜法制备氧化锌压敏陶瓷粉料的研究(Ⅱ)

本文在前期研究工作的基础上 ,重点研究了五元掺杂组分共沉淀包膜ZnO微粒的过程中各种因素对粉料mol%配比、粒度分布、颗粒形状及电性能的影响 ,优化工艺参数 ;对三种制粉方法的压敏陶瓷电性能进行了比较 ,在此基础上建立氧化锌压敏陶瓷制粉新方法。     

Al掺杂纳米氧化锌导电粉的性能与结构

以Zn( NO3)2·6H2O,Al(NO3)3·9H2O,尿素为原料,采用均相沉淀法,制备出碱式碳酸锌粉末,之后将前驱体在氢气气氛下煅烧,制得Al掺杂氧化锌导电粉.利用SEM,TGA,XPS和XRD等分析手段对材料性能进行表征,研究了Al掺杂氧化锌导电性能的影响.结果表明:随着Al3+掺杂量的增大,粉体体积电阻率先降低后升高,Al3+掺杂含量在1.5％(摩尔分数)时电阻率最低,为1.05×105Ω·cm.掺杂后的ZnO为六方纤锌矿结构,颗粒呈类椭球形,粒度分布窄,导电性能明显提高.     

三氧化钨薄膜的光学特性和结构研究

用溶胶-凝胶法和直流反应磁控溅射法制备了表面均匀致密的三氧化钨薄膜,并用双光束紫外可见分光光度计和X衍射分别对薄膜的透光性、结构形态进行了测定;描述了退火温度对薄膜透光性和结构形态的影响,结果表明在高温(＞300℃)退火处理后薄膜的透光率下降,且退火温度越高透光率越低;在350℃以下退火处理后得到薄膜样品为非晶态,在350～400℃范围内退火处理,样品由非晶态向晶态转变.     

脉冲磁控溅射制备硼掺杂氧化锌纳米薄膜的光学特性研究

采用脉冲磁控溅射法制备硼掺杂氧化锌（ZnO：B）纳米薄膜,研究了其结构和光学特性,经XRD分析,ZnO：B为多晶纳米薄膜,具有六方钎锌矿结构,薄膜沿着c轴取向择优生长。薄膜在可见光和近红外光谱区的透光性很好,其中在可见光区的平均透光率可达84％以上,而在近红外区的透光率随着波长增加而逐渐降低至45％。在可见光区,ZnO：B纳米薄膜的光学常数随波长的变化很小且数值基本趋于恒定,而在紫外区,光学常数随波长的变化很明显,并且在367nm和397nm附近存在两个紫外发光峰。     

热氧化处理对铋薄膜光学性能的影响

对通过蒸发获得的金属铋薄膜经加热氧化处理并与直接蒸发氧化铋获得的薄膜比较和进行光学性能测量，发现都能获得β相氧化铋薄膜。但是由于热氧化与蒸发的过程或速率不同，出现化学计量偏离，薄膜结构和光学性能变化。热氧化不够或低速率蒸发形成薄膜富铋，出现无定型或其它相结构，光学吸收限变宽，移向低能处。过氧化则会使薄膜富氧，同样使结构变化，吸收限变宽而向高能方向移动。实验表明蒸发金属铋薄膜然后经３５０℃，３小时热氧化是比较合适的制备氧化铋薄膜的条件。     

纳米ZnO对炻瓷砖烧结性能及相变的影响

以六偏磷酸钠在水相中分散纳米氧化锌,并将其添加到炻瓷砖原料中。研究了纳米ZnO的添加量对炻瓷砖的烧结温度、保温时间和烧结后性能的影响。结果表明,在瓷砖粉料中添加纳米氧化锌可显著降低炻瓷砖的烧结温度并缩短保温时间。通过对瓷砖吸水率、破坏强度及尺寸的测量,得出随纳米氧化锌添加量的增加,瓷砖吸水率显著降低,破坏强度升高,而瓷砖尺寸有明显的收缩,使得瓷砖结构致密化。最佳的实验条件是:烧结温度为1050℃,纳米氧化锌浓度为3%,烧结段保温时间为9min。通过对不同烧结温度下材料的相组成进行分析,发现添加纳米氧化锌促进了堇青石(Mg2Al4Si5O18)的分解或加合,促进了锌铝尖晶石(ZnO.Al2O3)和鳞石英的形成,且随着添加量增加,堇青石加合、锌铝尖晶石和鳞石英形成的温度降低,有利于炻瓷砖的烧结。     

铝钼共掺杂氧化锌粉末的制备及光电性能研究

采用水热法制备了不同含量的铝(Al)单元掺杂及铝(Al)、钼(Mo)共掺杂氧化锌(AZO、AZMO)纳米粉体,利用X射线衍射(XRD)、扫描电镜(SEM)、高分辨透射电镜(HRTEM)、荧光分光光度计(PL)、紫外分光光度计(UV-vis)、TG-DTA差热分析、激光粒度分析仪、四探针电阻测试仪等测试手段,探究了Al单元掺杂和Al、Mo共掺对AZO、AZMO粉体结构、形貌及光电性能的影响.结果表明:所制备的AZO和AZMO纳米粉体为结晶度良好的六方纤锌矿结构.Al、Mo掺杂浓度影响纳米氧化锌粉体形貌、晶体结构及光电性能.随着Al、Mo掺杂浓度的增加,粉体的结晶质量降低,晶粒尺寸先减小后增大,光电性能先变好后变差.适度的Al、Mo共掺杂可使氧化锌禁带宽度和电阻率达到最优匹配,改善氧化锌的近紫外发光和蓝色发光特性.在掺杂浓度为m(Al):m(Mo)=1:3时,纳米粉体的综合光电性能最佳,禁带宽度为3.392 eV,电阻率为20.3Ω·m,紫外发光峰强度最大,且出现了蓝移.     

热喷涂纳米陶瓷涂层的制备及性能

热喷涂纳米陶瓷涂层的研究是目前陶瓷涂层领域研究热点之一.介绍了国内外热喷涂纳米陶瓷涂层的主要制备方法及涂层性能,重点介绍了可喷涂纳米结构喂料的主要制备方法和工艺路线.与传统微米级陶瓷涂层相比,纳米陶瓷涂层具有更为优异的性能和广阔的发展前景.     

热处理对氧化锌纳米线场发射特性的影响

用场发射显微镜研究了在钨针尖上生长的氧化锌纳米线的场发射性能,得到了氧化锌纳米线的场发射像及场发射电流与电压关系,并讨论了氧化锌纳米线场发射像的形成原因和不同热处理条件对其场发射性能的影响,给出了氧化锌纳米线比较合适的热处理温度.