低成本电化学法制备RE2Zr2O7缓冲层

为了降低第二代高温超导涂层导体的制备成本,采用电化学法(ED),在双轴织构的Ni-5at%W(Ni-5W)金属基带上分别成功制备出了具有较好c轴取向的La2Zr2O7(LZO)和Gd2Zr2O7(GZO)缓冲层.通过与磁控溅射方法(MS)相结合,制备出MS-CeO2/ED-RE2Zr2O7双层结构,用以取代完全用磁控溅射方法(MS)制备的多层缓冲层结构.电化学法得到的60 nm LZO缓冲层的面内和面外织构半高宽分别为7.2°和6.8°,同样厚度的GZO缓冲层的面内和面外半高宽分别为6.7°和5.8°.之后用脉冲激光沉积(PLD)在ED-LZO/Ni-5W,ED-GZO/Ni-5W,MS-CeO2/ED-LZO/Ni-5W三种结构的缓冲层上分别制备出具有超导性能的YBa2Cu3O7-δ(YBCO)超导层.     

Ni包裹Al2O3复合粉体的制备

采用非均相沉淀工艺在Al2O3颗粒表面均匀地包裹上镍盐前驱体,经煅烧、还原后得到纳米晶Ni包裹Al2O3复合粉体.相分析表明,非晶态的镍盐前驱体在550℃已转变为NiO,再经700℃氢气处理后,NiO还原为Ni,其晶粒尺寸约为20nm.结构分析表明,复合粉体在热处理过程中,包裹层由连续态变为非连续态.     

化学溶液沉积法制备Y2O3过渡层

为了满足YBa2Cu3O7(YBCO)超导带材生产实际的需要,在金属基带和YBCO超导薄膜之间制备一层合适的氧化物过渡层显得尤为重要。以乙酸钇为原料配制前驱体溶液,采用金属盐化学溶液沉积法在织构的Ni-5%W(质量分数)(Ni-5W)带上成功制备了Y_2O_3过渡层。结果显示,氮气氛下1050℃热处理1h后,所获得的Y_2O_3过渡层具有良好的晶体织构,晶体生长取向为(100),完全复制了Ni-5W带模板的结构,为YBCO生长提供了良好的模板。在Y_2O_3过渡层上制备的YBCO薄膜表现出良好的超导性能。     

Ni包裹Al2O3复合粉体的制备

采用非均相沉淀工艺在Al2O3颗粒表面均匀地包裹上镍盐前驱体，经煅烧，还原后得到纳米晶Ni包裹Al2O3复合粉体，相分析表明，非晶态的镍盐前驱体在550℃已转变为NiO，再经700℃氢气处理后，NiO还原为Ni，其晶粒尺寸约为20nm。结果分析表明，复合粉体在热处理过程中，包裹层由连续态变为非连续态。     

水热前驱体法制备钙钛矿相Pb(Ni1/3Nb2/3)O3(PNN)

以五氧化二铌(Nb2O5)为原材料通过络合反应合成了铌的前驱体溶液,并与醋酸铅(Pb(Ac)2),醋酸镍(Ni(Ac)2)混合,于200℃水热条件下进行预反应.水热预产物经进一步煅烧,成功获得了纯钙钛矿相PNN粉体.采用XRD和Raman分析,研究了水热时间,溶液pH值,煅烧温度等条件对PNN粉体相结构的影响,分析了粉体的相结构变化规律.结果表明,经过水热处理的粉体,在900℃煅烧后,形成具有钙钛矿结构PNN,特别是通过调整制备工艺,得到纯相的PNN粉体.     

强立方织构Ni-40%Cu-3%W及复合基带的制备

本工作采用轧制辅助双轴织构技术(RABiTS)制备了无铁磁性的Ni-40%Cu-3%W合金及Ni-40%Cu-3%W/Ni9W/Ni-40%Cu-3%W复合基带。采用X射线衍射技术(XRD)及背散射电子衍射技术(EBSD)对Ni-40%Cu-3%W合金基带再结晶热处理后的织构进行了表征,结果表明,对Ni-40%Cu-3%W合金基带进行再结晶退火后(1 050 ℃保温60 min),合金基带表面形成了锐利的立方织构。此外,采用粉末冶金技术制备出了Ni-40%Cu-3%W/Ni9W/Ni-40%Cu-3%W合金复合坯锭,并采用RABiTS技术制备出了无铁磁性的复合基带,其室温下的屈服强度为255 MPa,明显高于商业化生产的Ni5W合金基带的屈服强度,弥补了Ni5W合金基带在磁性能和力学性能上的不足。     

热处理对V2O5-TiO2复合薄膜表面结构与光学性能的影响

以钛酸丁脂、V2O5粉末为前驱体,采用溶胶-凝胶法制备了V2O5-TiO2复合薄膜,并采用X射线光电子能谱(XPS)和Uv-vis-nir分光光度计等方法研究了热处理对薄膜性能的影响.结果表明,随热处理温度的升高,复合薄膜中钛离子的价态不变,仍为Ti4 ;而V4 离子逐渐被氧化为V5 离子;并采用氢氧基团、碳氧键与多种钒离子进行叠加拟合,拟合结果与实验曲线非常符合;V2O5-TiO2复合薄膜在紫外光波段的透射率减小,吸收带边出现红移.     

化学溶液沉积法La2CuMnO6缓冲层薄膜的制备与结构表征

根据镧、铜及锰盐在不同溶剂中的溶解性,选择合适的溶剂及镧、铜及锰盐为前驱体,配制成前驱溶液进行润湿性、稳定性及不同衬底热处理实验,成功筛选出制备La2CuMnO6(LCMO)缓冲层薄膜的前驱体,利用X射线衍射(XRD)和原子力显微镜(AFM)对化学溶液沉积法(CSD)合成的La2CuMnO6薄膜的相组成和形貌结构进行了表征。结果表明,选择合适的前驱体(La(CH3COO)3·1.5H2O、Cu(CH3COO)2·1.0H2O、Mn(CH3COO)2·4.0H2O)及SrTiO3(STO)(100)衬底,在1000℃、保温时间3h、空气气氛及总离子浓度为1.0mol/L工艺条件下制备的La2CuMnO6薄膜具有很好的c轴织构,薄膜表面较平整、均匀、无裂纹、无孔洞,分布均匀且排列致密,完全满足缓冲层对薄膜的要求。     

Mn~(2+)(Co~(2+)Ni~(2+))O_4材料制备中前驱物的影响

采用水热合成法,以Mn、Co、Ni的有机或无机盐和氨水为反应原料,通过调控前驱物配方、浓度等工艺参数在一定水热反应条件下,制备纳米粉体材料,利用XRD、TEM等手段分析了该粉体的晶相及杂质组成等性能参数.实验结果表明,采用硝酸盐和沉淀剂配制、中等盐溶液浓度的前驱物,在合适的条件下进行水热反应,合成了单一尖晶石结构、晶粒尺寸集中在20～50nm间的Mn~(2+)(Co~(2+)Ni~(2+))O_4粉体材料.     

加工率对Ni5W合金基带立方织构的影响

以镍粉和钨粉为起始原料,采用粉末冶金的方法形成Ni5W预合金锭,采用真空电弧炉去除杂质,实现均匀化。结合热轧、冷轧和再结晶热处理等工艺制备了厚度为80μm的Ni5W合金基带。讨论了道次加工率、总加工率对Ni5W合金基带轧制织构演变的影响。结果表明,较小的道次加工率和较大的总加工率有利于基带再结晶热处理后立方织构百分含量的提高,道次加工率对立方织构质量的影响小于总加工率。以5%的道次加工率和98%的总加工率进行冷轧后,获得了具有较高含量的S型织构和Copper型织构的基带。     

溶胶-凝胶法制备YBa2Cu3O7-x超导薄膜的研究

传统的TFA-MOD法制备YBa2Cu3O7-x薄膜,采用Y、Ba、Cu 3种金属的三氟醋酸盐(TFA)为先驱体,在热分解时,会产生大量的HF气体,即使通过将近20h的缓慢升温过程来对薄膜进行热分解,也难以获得较为光洁的表面,从而无法实现厚膜的制备.本文提出了一种新的含氟溶胶-凝胶工艺,通过减少溶胶中F的含量,并利用二乙醇胺做修饰剂,缩短了热分解时间,提高了薄膜的表面光洁度.利用该方法在(010)LaAlO3衬底上制备了具有良好c轴取向,临界转变温度为89K的YBCO超导薄膜.     

Ni掺杂TiO2薄膜的甩胶喷雾热分解法制备和自清洁性能的研究

以钛酸丁脂（Ti（C4H9O）4）为先驱体,硝酸镍（NiNO3）为掺杂物,采用甩胶喷雾热分解方法在玻璃衬底上制备出了镍掺杂TiO2自清洁薄膜,通过扫描电镜（SEM）、X射线衍射（XRD）、紫外-可见透射光谱（UV-Vis）、光催化和亲水性能测定等手段对样品进行分析,结果表明,500r/min为理想衬底转速,350℃是理想的衬底沉积温度,500℃是理想的样品退火温度。随着镍掺杂量的不断增加,TiO2薄膜的亲水性能也越好,当镍掺杂量达2%-3%时,TiO2薄膜的亲水性能达到最好。     

The degradation of novolak containing metal nitrates and the formation of YBCO

Polymers that form a complex with metal ions from nitrate salts can be used to prepare precursors for the production of high temperature superconductor (HTSC) ceramics that can be processed using advantageous polymer processing techniques and then pyrolyzed. This paper describes the production of HTSC from a precursor based on m-cresol formaldehyde novolak resin (mCFNR) that contains yttrium, barium and copper nitrate salts in the proportions needed for the formation of YBa₂Cu₃O_7−x (YBCO). The degradation of the precursor and the effects of the pyrolysis process (temperature, time, environment, substrate) were studied in detail. The mechanisms of degradation for mCFNR and for the HTSC precursors were significantly different with the precursor degradation beginning at significantly lower temperatures. The optimal pyrolysis begins in an inert atmosphere to hinder BaCO₃ formation and then continues in oxygen to 950 °C. A dense orthorhombic YBCO film with preferential [001] orientation results from topotaxial growth on SrTiO₃.     

喷雾热分解法制备SnO2透明导电薄膜

利用压缩空气气雾化器,通过喷雾热分解法,以ＳｎＣｌ２．２Ｈ２Ｏ为原料,在载玻片上成功制备了ＳｎＯ２薄膜,在１１０℃到３６５℃间的不同沉积温度下进行镀膜,考察了沉积温度,沉积时间对ＳｎＯ２薄膜制备的影响,结果表明,在３２５℃的沉积温度下,薄膜已晶化,随着温度升高,喷雾时间增加,方块电阻降低３２５℃下的样品在可见光区透射率达８０％以上,近红外区透射率达９０％以上。     

Perovskite-type lanthanum chromium-based oxide films prepared by ultrasonic spray pyrolysis

Ultrasonic spray pyrolysis was used to form 2–8 m thick LaCrO₃ films on different substrates from La(CrO₄)(NO₃)·nH₂O precursor films. There was an optimum substrate temperature for the formation of uniform precursor films by the spray pyrolysis. When the substrate temperature was lower than 250 °C, dry precursor films were not formed, while above 250 °C the deposition rate decreased with substrate temperature. The precursor films were converted to perovskite-type oxide films by heat treatment at 800 °C in a nitrogen atmosphere. Both A-site substituted (La_0.8Ca_0.2) CrO₃ and B-site substituted La(Cr_0.5Mn_0.5)O₃ oxide films were formed in a similar manner. Electronic conductivity of the oxide films was improved by repetitions of the spray pyrolysis and heat treatment in nitrogen.     

硫化温度对CuInS2薄膜微结构和光学性能的影响

采用磁控溅射法在玻璃衬底上沉积Cu-In合金预置膜,采用固态硫源在N2气氛下硫化热处理的方法制备了CuInS2薄膜。研究了硫化温度对CuInS2薄膜的晶相结构、表面形貌和光学带隙等性能的影响。采用X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、紫外-可见光谱(UV-Vis)等测试手段对薄膜的晶相结构、表面形貌、光学性能进行了表征。结果表明,Cu-In合金预置膜经550℃硫化热处理20min可制备出黄铜矿结构的CuInS2薄膜,并具有(112)面的择优取向,所制备的CuInS2薄膜晶粒粒径约为1μm,光学带隙为1.51eV。     

Initial stages of deposition and film formation during spray pyrolysis — Nickel oxide, cerium gadolinium oxide and mixtures thereof

The formation of nickel oxide (NiO), cerium gadolinium oxide (CGO) and NiO-CGO thin films by air blast spray pyrolysis was studied at two scales. First, single droplets of precursor were deposited on sapphire substrates and the morphology of the formed residue was studied as a function of the substrate surface temperature, type of metal salt, salt saturation, and organic solvent in the precursor. Second, the synthesis of continuous films from repetitively deposited droplets and crack formation in the films were studied as a function of substrate temperature and salt decomposition kinetics. Nitrates, acetates, perchlorates and chlorides of nickel, cerium and gadolinium were the metal salts used, and mixtures of ethanol or water with di-, tri- and tetraethylene glycol were used as solvents.Regular ring- or disc-shaped deposits were formed from single droplets that evaporated without boiling and were mainly observed with metal acetate- and chloride-based spray solutions or at low substrate temperatures. Disc-shaped residues were obtained for saturated salt solutions and changed to rings with diminishing rim thickness with decreasing salt saturation. The formation of bubbles in the droplet from boiling or salt decomposition during evaporation resulted in the distortion of the circular shape and was predominantly observed for metal nitrate-based precursors and at high substrate surface temperatures.Continuous, dense and crack-free films of CGO and NiO-CGO with thicknesses up to 500 and 800 nm, respectively, were prepared from metal nitrate/chloride mixtures in a tetraethylene glycol-based solvent. The maximum crack-free thickness decreased with decreasing deposition temperature and was correlated to the metal salt decomposition kinetics.     

先驱体转化法制备 2D C/SiC-ZrB2复合材料及其性能

针对高超音速飞行器、可重复使用运载器和下一代火箭发动机等超高温使用环境的工况要求,提出在2D C/SiC复合材料体系中引入耐超高温相ZrB₂。采用先驱体转化法制备了不同ZrB₂含量的2D C/SiC-ZrB ₂新型复合材料,考察了ZrB₂含量对材料力学性能、微观结构和抗烧蚀性能的影响。结果表明,材料的力学性能(弯曲强度和弯曲模量)随着材料中ZrB₂含量的增加有一定的下降,材料的抗烧蚀性能明显提高。其中含ZrB₂体积分数为19.4%的试样弯曲强度达到242.6MPa,弯曲模量为37.1GPa;经氧乙炔焰烧蚀考核90 s后,试样表面温度达到2329℃,线烧蚀率为0.015 mm/s,质量烧蚀率为 0.005g/s。     

铝合金表面超疏水涂层的火焰喷雾热解法制备及其耐蚀性能

采用火焰喷雾热解与表面修饰相结合的方法在铝合金表面制备了具有一定耐蚀性能的超疏水表面。以六甲基二硅氧烷溶液为前驱液,通过火焰喷雾热解方法,首先在铝合金表面沉积SiO2纳米颗粒构建粗糙结构,再以氟硅烷溶液进行表面修饰,获得了具有154.9°静态接触角,滚动角<2°的超疏水表面。通过电化学测试,对比了构筑超疏水表面前后的铝合金样品的耐蚀性能。结果表明沉积层与低表面能物质协同作用,通过对腐蚀性离子的有效隔离,提高了铝合金基体的耐蚀性能。     

Preparation of ceria films by spray pyrolysis method

The deposition of CeO₂ films on fused-silica substrates by spray pyrolysis of a water–ethanol solution of a cerium nitrate precursor has been studied. Polycrystalline films have been obtained at a substrate temperature of 300–450°C after annealing of the deposit in air at temperatures in the range 350–500°C. It has been established that the best uniform ceria films with nanometric scale grains are prepared at a substrate temperature of 400°C with 0.5 h annealing of the deposit at 500°C. At lower spraying temperatures large CeO₂ crystallites have been observed on the film surface along with the fine grains. When the substrate temperature exceeds 400°C, numerous cracks caused by thermal stresses appear in the films.