Shuming Wang Fenghua Kuang
材料科学技术（英）
Boron for aluminum substitution in the cordierite structure has been examined by sol-gel preparation of different samples along the compositional junction Mg2Al4-xBxSi5O18 with x=0, 0.5, 1, 1.5. By increasing the x value from 0 to 1.5 the crystallization behavior changed accordingly. Proper amount B2O3 doping can promote the sintering of amorphous cordierite gel, effectively restrain the precipitation of μ-cordierite and enhance the crystallization of α-cordierite. The substitution of B3+ for Al3+ in cordierite crystal structure can effectively improve the near-infrared spectral emissivity of this cordierite based glass-ceramics.
关键词:
Sol-gel
,
Glass-ceramics
,
Infrared radiation
,
B3+-substituted
,
Solid solution
M. Thambidurai N. Murugan N. Muthukumarasamy S. Agilan S. Vasantha R. Balasundaraprabhu
材料科学技术（英）
Nanocrystalline CdS thin films have been deposited using precursors with different thiourea concentration onto glass substrates by sol-gel spin coating method. The crystalline nature of the films has been observed to be strongly dependent on thiourea concentration and annealing temperature. The CdS films are found to be nanocrystalline in nature with hexagonal structure. The grain size is found to be in the range of 7.6 to 11.5 nm depending on the thiourea concentration and annealing temperature. The high resolution transmission electron microscopy (HRTEM) results of the CdS films prepared using cadmium to thiourea molar ratio of 0.3:0.3 indicate the formation of nanocrystalline CdS with grain size of 5 nm. Fourier transform infrared (FTIR) analysis shows the absorption bands corresponding to Cd and S. The optical study carried out to determine the band gap of the nanostructured CdS thin films shows a strong blue shift. The band gap energy has been observed to lie in the range of 3.97 to 3.62 eV following closely the quantum confinement dependence of energy on crystallite radius. The dependence of band gap of the CdS films on the annealing temperature and thiourea concentration has also been studied. The photoluminescence (PL) spectra display two main emission peaks corresponding to the blue and green emissions of CdS.
关键词:
Sol-gel
,
CdS quantum dots
,
HRTEM.
初瑞清
,
徐志军
,
李国荣
,
殷庆瑞
材料研究学报
将湿化学法中的sol-gel技术与声化学中的超声雾化技术相结合,提出一种新的陶瓷粉体合成方法-湿声化学法, 并制备了PZT(52/48)粉体.结果表明, 用湿声化学法制备PZT(52/48)粉体, 在400℃开始形成PZT钙钛矿相,比其它制备方法的温度(500-900℃)低, 在700℃保温2 h即可得到具有纯PZT结构相的粉体.用湿声化学法制备的粉体颗粒呈圆形, 粒径小于1 um.湿声化学法使用不溶性盐ZrO2而不是sol-gel方法中必须使用的可溶性盐,从而降低了成本.
关键词:
无机非金属材料
,
Sol-gel
,
Wet-acoustic chemical method
,
Ultrasonic atomization
马广
,
赵景畅
,
吴兴惠
材料导报
以硝酸钙、硝酸铜、钛酸四丁酯、冰乙酸和无水乙醇为原料,采用溶胶-凝胶自蔓延燃烧反应成功地制备了平均粒径为60～80nm的CaCu3Ti4O12纳米粉体.采用XRD、TEM和IR对纳米粉体的结构、形貌和光谱特性进行了分析和表征,并借助TG-DSC研究了干凝胶的自蔓延特性和晶化过程.采用传统烧结工艺制备了陶瓷,测得其在室温、lkHz时的介电常数为6×104.
关键词:
Sol-gel
,
白蔓延燃烧
,
CaCu3Ti4O12
,
介电性能
周宏明
,
易丹青
,
余志明
,
肖来荣
,
李荐
,
王斌
金属学报
采用溶胶-凝胶法制备了ZnO∶Al(AZO)透明导电薄膜.通过X射线衍射(XRD)、紫外-可见分光光度计(UV-Vis)、扫描电镜(SEM)和电阻测量装置, 考察了Al掺杂量、退火温度及镀膜层数等工艺参数对薄膜的微观结构和光电性能的影响. 结果表明,退火温度越高, 多晶AZO薄膜的(001)晶面择优取向生长的趋势越强, 并且随退火温度升高,薄膜的晶粒尺寸增大, 透光率增加. 薄膜晶体结构为纯ZnO的六角纤锌矿结构. 在掺杂浓度1%(摩尔分数)、退火温度500℃及镀膜层数10的条件下, 得到了电阻率为3.2×10-3 Ω•cm、可见光区的平均透射率超过90%的AZO薄膜.
关键词:
ZnO∶Al(AZO)薄膜
,
Sol-gel
王晓强
,
甄聪棉
,
李明亚
稀有金属材料与工程
利用SO1-Gel二步水解法制备了TiO2/SiO2复合薄膜材料,对样品在空气气氛中进行加热,再于不同温度下进行了退火处理.采用XRD以及Raman谱表征了样品的微结构,并通过紫外可见透射谱研究了样品的光学特性.结果表明,样品的光学特性与样品中SiO2含量存在依赖关系,并分析了相应机理.
关键词:
Sol-gel
,
TiO2/SiO2
,
复合薄膜
,
光学特性
陈东初
,
王哲
,
郑家燊
,
傅朝阳
功能材料
利用离子交换法制备了WO3的Sol溶液,并应用于H+选择性电极的敏感膜.电极有良好的H+响应,响应pH值范围为2～11,响应灵敏度约为52mV/pH.本文利用TG、DSC、IR、SEM、AFM、XRD等分析手段对WO3膜的组成与形态进行了表征,WO3形貌为龟裂泥土状,膜的组成为WO3、WO3·H2O或WO3·0.33H2O,随着热处理温度的提高,结晶水减少.EIS图谱表明电极的H+响应动力学过程为H+扩散过程控制,H+扩散系数为10-10cm2·S数量级.
关键词:
Sol-gel
,
WO3
,
pH电极
,
机理
张朋越
,
钟伟
,
蒋继峰
,
洪樟连
稀有金属材料与工程
采用Sol-gel方法合成了Al和Pr离子共掺的红色纳米晶SrTiO3:0.002Pr,xAl(x=0～0.35)荧光体.XRD分析表明,经1200℃高温烧成后所得的荧光体为单一组成的SrTiO3立方相,空间群为Pm-3m,晶胞参数计算得α为3.9043 nm.光谱测试表明,该荧光体的主发射峰位于617nm,对应于Pr3+离子的1D2→3H4跃迁发射.随着Al3+掺杂浓度的增加,发光强度先增后减,当x=0.26时发光强度达到最大值,此时荧光体的发光强度约是未掺Al样品发光强度的2倍.晶体结构和光谱性能分析暗示,Al3+离子掺入可能提高了SrTiO3:Pr基质晶体的完整度,从而增加其发光强度.
关键词:
SrTiO3 Pr
,
Sol-gel
,
发光
,
荧光粉
陈永毅
,
唐电
,
邵艳群
,
王欣
稀有金属材料与工程
采用热分解法和Sol-gel法,制备了具有三明治涂层结构的Ru-Ti-Ir-Ta/Ti四元金属氧化物钛阳极.采用XRD和SEM方法分析了涂层的相组织结构特征,通过Tafel曲线和循环伏安曲线的测试研究并比较了涂层的电催化活性.结果表明,两种方法制备的阳极涂层相成分都以 (Ir, Ta)O2和(Ti, Ru)O2金红石固溶体相为主.在热分解法制备的涂层中还存在单质金属钌.采用Sol-gel法制备涂层,其晶粒更为细小.采用热分解法和Sol-gel法制备的钛阳极涂层表面形貌有明显的不同,前者可见明显的"泥裂状"裂纹,后者呈碎石状.采用Sol-gel制备的钛阳极比热分解法制备的钛阳极具有更好的电催化活性和耐蚀性.
关键词:
热分解法
,
Sol-gel
,
钛阳极
,
电催化活性
Yunfeng Zhao
材料科学技术（英）
Modified TiO2 films have been prepared by combining commercial titania powders (Degussa P25) with sol-gel made by titanium chloride (Ti-sol). The result shows that clusters are formed by nanoparticles and large pores can be seen on the surface of the TiO2 films. The short circuit photocurrent density and photoelectric conversion efficiency of the solar cells are obviously enhanced compared with those without modification. The relationship between the photoelectric conversion efficiency and the amount of Ti-sol was investigated. With the addition of 30 wt% Ti-sol, the photoelectric conversion efficiency as high as 9.75% is achieved, increasing by 28.3% compared with the solar cells without modification.
关键词:
Sol-gel
