直流电弧法回收ITO废靶技术研究

本文提出一种新型的ITO废靶回收技术,采用直流电弧法将ITO废靶气化制成纳米ITO粉末,实现废靶的回收.借助XRD(X射线衍射)和TEM(透射电子显微镜)等技术对粉末进行表征,发现经回收制备的ITO粉末为单一的立方In2O3结构,颗粒多以四方和类球形两种形貌存在,粒度尺寸在5- 200nm范围内.     

自燃/球磨法制备NiZn系铁氧体

以金属硝酸盐和柠檬酸为原料,用溶胶凝胶自燃烧法制备NiZn系铁氧体前驱体粉末(Ni0.4Zn0.6Fe2O4,Ni0.2Zn0.6Cu0.2Fe2O4,Ni0.33Zn0.59Cu0.11Fe1.97O4(Bi2O3)0.002和Ni0.33Zn0.59Cu0.11 Fe1.97O4(Bi2O3)0.002(MnO2)0.02),然后经30小时高能球磨,从X-ray衍射谱中发现前驱体粉末虽然基本上是尖晶石结构,但是还有一些杂相,经过球磨,杂相明显减少,结构更加完整,颗粒减小.前驱体粉末Ni0.33Zn0.59Cu0.11Fe1.97O4(Bi2O3)0.002经30小时球磨后,在空气中退火,退火温度分别为400℃,600℃,800℃,900℃,1000℃.用X-ray衍射谱分析其物相,发现在800℃退火得到单相的尖晶石结构,无杂相.该样品的最佳退火温度低于1000℃.用振动样品磁强计分别测量制备态和退火态样品粉末的磁性,可以看出,随退火温度的升高,比饱和磁化强度σs逐渐增大,矫顽力Hc逐渐减小,当900℃退火后,比饱和磁化强度已接近块状NiZn系铁氧体.1000℃退火后,上述四种样品中Ni0.4Zn0.6Fe2O4具有最高的比饱和磁化强度σs=65.09emu/g.本文为NiZn铁氧体的低温烧结提供了有用的实验数据.     

退火温度对透明导电Ga_2O_3/ITO周期多层膜性能的影响

用射频磁控溅射Ga2O3陶瓷靶材和直流磁控溅射ITO靶材在石英玻璃衬底制备Ga2O3/ITO周期多层膜。样品在300~800℃真空退火1小时,研究退火温度对薄膜光学和电学性能的影响。400℃退火的Ga2O3/ITO周期多层膜面电阻和电阻率低至68.76Ω/□和3.47×10-3Ω·cm,载流子浓度和霍尔迁移率高达1.30×1020cm-3和14.02cm2 V-1s-1。退火温度超过500℃后,Ga2O3膜层和ITO膜层之间开始相互扩散,薄膜结晶质量和导电性变差。所有退火薄膜在紫外-可见光范围的平均光学透过率高于83%,光学带边吸收随退火温度增加发生蓝移,光学带隙从4.59eV增加到4.78eV。     

电弧气化法制备纳米ITO粉末及高密度ITO靶的研制

以纯度为99．99％的纯金属In和Sn为原料,采用电弧气化法制备了单一立方In2O3结构的纳米ITO合金粉末,所制备的粉末以四方和类球形两种形貌存在,粒度主要位于30-70nm,分散性良好;并在此基础上采用常压烧结制备了相对密度高达99．74％,平均电阻率达到1．52×10^-4Ω·cm,结构成份均匀,晶粒尺寸5—10μm左右的超高密度ITO靶材。     

退火处理对铟锡氧化物粉末的影响

对两种不同比表面积(BET)的铟锡氧化物(ITO)纳米粉末进行退火处理,研究和比较了温度对两种粉末微观组织和结构的影响,并对这两种粉末烧结的靶材进行了比较。结果表明,在800～1500℃进行不同温度的退火处理后,在1200℃以上,两种比表面积的ITO粉末粒径增长显著,颗粒之间出现了相互合并和结合长大现象,而高BET粉末的粒径增加幅度比低BET粉末的更大;在1525℃烧结后,用高BET粉末烧成的靶材的晶粒和气孔尺寸更大,气孔数量也更多。     

分散剂对铟锡氧化物(ITO)粉末粒径的影响

以纯In、SnCl4·5H2O和盐酸为原料,氨水为沉淀剂,采用络盐法制备了纳米铟锡氧化物(ITO)粉末。主要研究了分散剂对ITO纳米粉体粒径的影响。用激光粒度仪、XRD、SEM对所得粉末进行表征。结果表明:随着分散剂的分子量的增加,所得ITO的粒径逐渐变小;加入不同分子量的PEG配合使用有利于制备纳米级颗粒,加入PEG(10000∶6000=1∶1)作分散剂所制ITO粉末粒径为50～100nm。     

甩胶喷雾热分解法制备ITO薄膜及光电性能研究

按In:Sn(物质的量比)=9:1,InCl3·4H2O和SnCl4·5H2O为前驱物,采用自制甩胶喷雾热分解制备薄膜装置在普通玻璃衬底上沉积了ITO薄膜,结果表明,采用自制甩胶喷雾热分解制备薄膜新装置成功制备出ITO薄膜。该装置结构简单、操作方便。制备ITO薄膜优化条件为:甩胶转速800r/min、衬底温度250℃、退火温度450℃、载气为空气、流量为7L/min、液体雾化速度0.2ml/min、雾粒速度3.5m/s。薄膜的沉积时间为5min,薄膜厚度约1000nm,最低电阻率为0.75*10-4Ω·cm,薄膜在可见光范围(波长在400-700nm)内平均透光率为87.2%。衬底温度在200℃以上时呈现立方相结构。     

退火处理对Y2O3薄膜结构和光学性能的影响

采用射频磁控溅射法以Y2O3陶瓷为靶材在单晶si(Ⅲ)和石英表面制备了Y2O3薄膜.利用X射线衍射(XRD)仪、扫描电子显微镜(SEM)、紫外-可见(UV-VIS)光谱仪和傅立叶变换红外(FTIR)光谱仪对真空退火前后Y2O3薄膜的结构和光学性质进行了分析研究.结构研究表明,在200℃条件下制备的Y2O3薄膜为非晶态,经600℃退火后出现单斜相,经800℃退火后薄膜完全转化为立方多晶,同时得到了不同晶面的晶粒尺寸;沉积态的Y2O3薄膜由球状颗粒排列组成,经800℃真空退火后薄膜为柱状晶.光学性质研究发现,真空退火后Y2O3薄膜的红外透过率显著下降;使用Tauc作图法得到不同结晶条件下的光学带隙,发现薄膜的光学带隙与结晶条件有关,并且退火后薄膜的光学带隙明显减小.     

ITO薄膜的微结构表征及其组分特性

用直流磁控溅射法制备了氧铟锡(ITO)薄膜。采用XRD、TEM、XPS对薄膜的微结构和化学组分进行了测试分析。分析结果表明:制备的薄膜中,Sn元素已固溶到In2O3晶格形成了多晶ITO。延长退火时间,薄膜的结晶度增加,SnO被氧化为SnO2并逐渐达到饱和,薄膜表面先失氧后附氧,膜中氧空位含量先增加后减少。退火1h后,薄膜具有最低电阻率(6×10-4Ω.cm)和高可见光平均透射率(93.2%)。     

制备条件和退火处理对Fex/(In2O3)1-x颗粒膜结构、磁性及巨磁电阻的影响

用射频溅射法成功制备了金属／半导体型颗粒膜Fex／(In2O3)1-x实验结果表明样品的微结构、磁性和巨磁电阻效应受制备条件(如本底真空度、衬底温度、溅射电压等)以及热退火处理的强烈影响。较高的衬底温度有利于基体In2O3的晶化和Fe颗粒的成长。适当的热退火能促使Fe颗粒生长，使晶格畸变减小，从而改善膜的微结构。室温下，磁性测量表明样品具有超顺磁性，符合朗之万方程。高温退火后，颗粒的大小已超过单畴粒子的临界尺寸，引起矫顽力下降。     

原位生成Al2O3/Cu复合材料的新工艺

采用一种新型工艺制备了Al₂O₃/Cu复合材料。高能球磨制备亚稳态的Cu-0.8 wt% Al合金粉,再将Cu₂O粉与其一起进行高能球磨,然后将复合粉末压坯在真空炉中同时进行氧化和烧结。该工艺省略了还原剩余Cu₂O的环节,氧化和烧结时间仅为1 h。生成的Al₂O₃的粒径约250nm,颗粒间距约500 nm,均匀弥散分布;该材料冷加工后性能接近SCM制品性能。该配比的Al₂O₃/Cu复合材料的热稳定性良好,在800℃下循环冷淬20次无裂纹;软化温度为700℃。     

Microstructure Evolution of Ti/BN Powder Blend during Ball Milling and Heat Treatment

Ball milled Ti/BN composite powder was prepared by high energy ball milling for 40 h, using Ti and BN (the molar ratio of Ti/BN is 3:2) as starting materials. The as-milled composite powder consists of TiN, Ti and amorphous phase. TiN formed while the milled powder was annealed at 400℃. The heat treatment at 700℃ led to the formation of TiB2 and TiB. The nanocrystalline Ti and amorphous phase converted to TiN and TiB2 when the powder was heated to 1300℃.     

Enhanced photoluminescence in Au-embedded ITO nanowires

Gold (Au)-embedded indium tin oxide (ITO) nanowires were synthesized by thermal evaporation of a mixture of In(2)O(3,) SnO(2) and graphite powders on Si (100) substrates coated with Au thin films followed by annealing. At the initial stages of annealing, Au formed a continuous linear core located along the long axis of each ITO nanowire. The morphology of the Au core changed from a continuous line to a discrete line, and then to a droplet-like chain, finally evolving into a peapod in which crystalline Au nanoparticles were encapsulated in crystalline ITO with increasing annealing temperature. The ITO nanowires with the Au core showed an emission band at ~380 nm in the ultraviolet region. The ultraviolet emission intensity increased rapidly with increasing annealing temperature. The intensity of emission from the Au-peapod ITO nanowires (annealed at 750 °C) was approximately 20 times higher than that of the emission from the Au-core/ITO-shell ITO nanowires with a continuous linear shaped-Au core (annealed at 550 °C). This ultraintense ultraviolet emission might have originated mainly from the enhanced crystalline quality of the annealed ITO nanowires.     

Effects of sintering processes on the element chemical states of In,Sn and O in ITO targets

The element chemical states of In, Sn and O could affect the resistivity of ITO targets so as to affect the electrical property of ITO films. In the work, nine kinds of ITO targets were prepared in order to investigate the effects of sintering processes on the element chemical states of In, Sn and O in ITO targets by XPS. The results show that the heating rate of 60 °C/h, the sintering temperature of 1580 °C, the holding time of 5 h and the cooling rate of 240 °C/h are favorable for the preparation of ITO targets with the optimum conductivity. The change rule of the element chemical states of In, Sn and O in ITO targets sintered with different sintering process parameters has been proved by the theoretical analysis of thermal decomposition kinetics of In₂O₃ and SnO₂.     

溶液燃烧法合成Co3O4纳米粉体及热处理研究

分别以氨基乙酸、柠檬酸、葡萄糖为燃料,Co(NO_3)_2·6H_2O为氧化剂,采用溶液燃烧法合成Co_3O_4粉体,并对氨基乙酸为燃料合成的Co_3O_4粉体在500℃、600℃和700℃热处理,研究其结构、微观形貌和磁学性能。研究表明各燃料配制的前驱体溶液在300℃均可发生燃烧反应合成Co_3O_4粉体,以氨基乙酸为燃料时,合成粉体的颗粒较大,中间有气孔,分散性好,残留少量的氨基乙酸。n(氨基乙酸)∶n(硝酸钴)=1.11∶1时合成的Co_3O_4粉体600℃热处理后得到了高纯度、分散性好、平均径向尺寸80nm的Co_3O_4纳米粉体。以氨基乙酸为燃料合成的Co_3O_4产物在600℃和700℃热处理后,其矫顽力和剩磁值都比500℃热处理后的要小。     

高能球磨时间和退火温度对制备TiNi合金粉的影响

为获得高能球磨时间和退火温度对TiNi机械合金粉特性的影响机制,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线能谱仪(EDS)、差示扫描量热法(DSC)等分析方法对TiNi合金粉进行了研究。结果表明,机械合金的相成分随着在氩气保护气氛中的球磨时间和退火温度的不同而发生变化。球磨22h的产物是非晶态TiNi合金、Ti的固溶体、Ni的固溶体,球磨27h的产物是非晶态TiNi合金粉和Ni固溶体相,球磨30h发生了明显的固相反应,生成了TiNi、Ni3Ti、Ti3Ni4等物相;在650℃/5h和1000℃/5h下的退火产物都是Ni3Ti、Ti2Ni、TiNi2、TiNi和TiC,但在上述2个退火温度下TiNi并不是主要物相,其中在650℃退火时TiNi的含量明显更低。     

High performance humidity sensing properties of indium tin oxide (ITO) thin films by sol–gel spin coating method

The tin doped indium oxide (ITO) thin films prepared by sol–gel spin coating method with In(NO₃)3H₂O and SnCl₄·5H₂O as indium and tin sources respectively is presented. The as deposited samples were annealed at 500 °C for 2 h in order to improve the crystallinity. The structural, morphological and optical properties of the films were analysed by using X-ray diffraction, scanning electron microscope (SEM), UV–Vis transmission spectra and photoluminescence, spectra analysis. The SEM images ensure the uniform and smooth surface of the as prepared and annealed film. The optical transmittance of more than 85 % has been observed in the UV–Vis region with a band gap of 3.91 and 3.73 eV for the as prepared and annealed films of ITO respectively. The PL spectra reveal that the optical properties were significantly improved due to the annealing effect. The annealed film shows high sensitivity for humidity approximately two order changes in the resistance and the sensitivity increases for different relative humidity from 10 to 90 % due to the physisorption between the water molecules and the surface of the thin films.     

Microstructure Characterization of Sol-gel Prepared MoO3-TiO2 Thin Films for Oxygen Gas Sensors

Binary metal oxide MoO3-TiO2 films have been prepared using the sol-gel technique. The thin films were annealed at several temperatures including 400℃,450℃,500℃,550℃ and 600℃ for lhour. The morphology, crystalline structure and chemical composition of the films have been analysed using SEM,XRD,RBS and XPS techniques. The SEM analysis showed that the films annealed at 450℃ are mainly smooth and uniform with 20-100nm-sized grains and with few particles as large as a micrometre or more. The XRD analysis revealed that the films annealed at 400℃ were a mixture of orthorhombic and hexagonal MoO3phases. The films annealed at 450℃ increased in hexagonal phase. The preferential orientation growth along(100) plane of the hexagonal phase and (010) plane of the orthorhombic phase has been found in both samples. RBS and XPS analysis showed that the films were stoichiometric. When the annealing temperature is increased to more than 500℃, the concentration ratio of MoO3 to TiO2 decreased due to the evaporation of MoO3. For the study of the electrical and gas sensing properties, films were deposited on sapphire substrates with interdigital electrodes on the front-side and a Pt heater on the backside. The O2 gas sensing properties of MoO3-TiO2 thin films are discussed.     

Fabrication of ZnO Nanoneedle/nanocolumn Composite Films and Annealing Induced Improvement in Their Microstructural and Photoluminescence Characteristics

ZnO nanoneedle/nanocolumn （NN/NC） composite films were grown via reactive electron beam evaporation （REBE） in the NH3/H2 gaseous mixture by using polycrystalline ZnO ceramic targets as source materials. The growth was performed at low substrate temperatures （450～500℃） without employing any metallic catalysts. As-prepared samples were then rapidly annealed in 02 ambient at a higher temperature （600℃）. Electron microscopic observations revealed the typical composite-structured morphologies of NN/NC/substrate of ZnO nanomaterials grown at 500℃. Such unique morphologies should render potential applications, for instance, as an efficient microwave absorption material utilized in the fabrication of concealed aerostat. In addition, X-ray diffraction and photoluminescence measurements showed remarkable improvement in crystal and optical qualities of ZnO NN/NC composite films after annealing.