共查询到19条相似文献,搜索用时 93 毫秒
1.
Raman光谱是研究纳米TiO2结构的最常用工具之一.纳米T2O2的Raman光谱研究是建立在以前对TiO2体材料的Raman光谱研究的基础之上.但是纳米TiO2与体相材料的表面性质和结构有较大的不同,其Raman光谱会产生明显变化.研究人员对纳米TiO2的Raman光谱已展开研究.本文概述了晶粒大小、结构、氧空位、退火温度、压力、相组成等因素对纳米TiO2的Raman光谱的影响. 相似文献
2.
水热法合成Nd(OH)3和Nd2O3纳米棒的形貌控制研究 总被引:1,自引:0,他引:1
以工业高纯氧化钕微粉为起始原料,在不使用表面活性剂的情况下通过简单的水热合成法制备出氢氧化钕一维纳米棒,采用X射线衍射仪、扫描电子显微镜和透射电子显微镜对其组成及形貌结构进行了系统表征.研究表明,合成过程中水热体系的反应温度、pH值、反应物初始浓度及反应时间对最终产物的形貌结构具有较大影响,当反应温度为180℃、溶液体系pH值约为9.5、Nd3 浓度为0.12mol/L时,经12h反应可以大量制备形态均一、相纯度高的六方相氢氧化钕晶体纳米棒.该氢氧化钕纳米棒在空气气氛下500℃焙烧后形成具有体心立方结构的C型Nd2O3,该Nd2O3仍具有一维纳米棒形貌. 相似文献
3.
4.
Raman光谱是研究纳米TiO2结构的最常用工具之一。纳米TiO2的Raman光谱研究是建立在以前对TiO2体材料的Raman光谱研究的基础之上。但是纳米TiO2与体相材料的表面性质和结构有较大的不同,其Raman光谱会产生明显变化。研究人员对纳米TiO2的Raman光谱已展开研究。本文概述了晶粒大小、结构、氧空位、退火温度、压力、相组成等因素对纳米TiO2的Raman光谱的影响。 相似文献
5.
6.
7.
Co-ZnO稀磁半导体纳米棒的水热合成研究 总被引:3,自引:0,他引:3
文章利用水热反应法制备出单晶结构的Co掺杂ZnO纳米棒,并对其形貌和结构进行表征。透射电子显微镜(TEM)结果表明,首先制备得到的纳米ZnO颗粒粒径分布窄,尺寸在50nm左右;用其作为生长Co-ZnO纳米棒的核而进一步反应得到的产物结晶完整,棒直径在40.70nm范围内,棒长一般在0.5μm左右,纳米棒沿着[001]方向生长。同时对反应中ZnO核以及PEG对纳米棒生长的影响进行了讨论。 相似文献
8.
9.
10.
采用水热法制备了CdSe纳米棒,并用TEM、SEM、XRD、TGA-DTA对其进行了表征.结果表明,纳米棒直径在100nm左右,长度约300nm;纳米棒具有闪锌矿的结构;将CdSe纳米棒均匀涂在导电玻璃的导电面上,在400℃下煅烧30min后制备成纳米棒膜电极,并进行了光电化学研究,纳米棒膜结构电极最高单色光的光电转换效率(IPCE)可达74%. 相似文献
11.
J. F. Peng X. J. Zheng Z. H. Dai 《Journal of Materials Science: Materials in Electronics》2014,25(1):414-418
The trilayered Bi3.15Eu0.85Ti3O12/Bi3.15Nd0.85Ti3O12/Bi3.15Eu0.85Ti3O12 (BET/BNT/BET) thin film was deposited on Pt/Ti/SiO2/Si(100) substrates by metal organic decomposition at annealing temperature of 650 °C, and the microstructure, chemical composition, leakage current, dielectric and ferroelectric properties were investigated by field emission scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, semiconductor characterization system, impedance analyzer and ferroelectric tester. The trilayered thin film is of crack-free and dense surface with some discrete cluster distribution, and typical Bi-layered perovskite polycrystalline phase. The dielectric constant ε r and dissipation factor tanδ are 1,233 and 0.0215 at 100 kHz for the trilayered thin film. Comparing with the pure BET and BNT thin films, the dielectric constant of trilayered thin film is enhanced, which is due to the space charge and the intermediate superlattice. The trilayered thin film shows excellent dielectric properties and can be promisingly used for the high dielectric layer of silicon-based embedded capacitors in package substrate. 相似文献
12.
13.
Single-crystalline Bi3.15Nd0.85Ti3O12 (BNdT) nanoplates of bismuth-layered perovskite structure have been synthesized through hydrothermal process. The BNdT nanoplates possess well-defined tetragonal shapes with landscape dimension of 100-600 nm and thickness of 10-30 nm. The in-plane surfaces of tetragonal-shaped nanoplates lies on (001), and the side surfaces are (110) and (110). The BNdT nanoplates were formed due to the rather higher growth rate of a-b plane than that of c-axis. The optical absorption characteristics in UV-visible region demonstrated that the band gap of the BNdT nanoplates is 3.33 eV. The absorption bands around 516 nm, 526 nm, 585.6 nm, 684.6 nm and 750 nm should be assigned as transitions of Nd3+ from the ground state 4I9/2 to 2G9/2, 4G7/2, 2G7/2 or 4G5/2, 4F9/2 and 4S3/2 states, respectively. 相似文献
14.
15.
《Materials Letters》2007,61(19-20):4166-4168
A thin-film bilayer structure consisting of polycrystalline Bi0.5Nd0.5Ti3O12 (BNdT) and preferential (111)-orientated Bi2Ti2O7 (BTO) has been prepared on n-type Si (100) substrate by a chemical solution deposition and spin-coating technique. The crystallization of BNdT film can be enhanced and the surface consists of larger grains because of the intervention of BTO. We fabricated the Au/BNdT/BTO/Si and Au/BNdT/Si structures, respectively. Compared with BNdT, the BNdT/BTO film shows better insulating and memory properties. The room temperature resistivity is 1011 Ω cm at a dc bias of 5 V. The C–V hysteresis curve is referred to as polarization-type switching and the memory window is about 3 V. All these results show that the BTO is an effective diffusion-barrier and plays a brilliant role as a seeding layer. 相似文献
16.
以金属醇盐和无机盐为原料,用溶胶-凝胶法合成了CaCu3Ti4O12干凝胶,进一步将干凝胶磨粉后在不同的温度煅烧不同的时间,得到相应的粉体样品.X射线衍射结果显示,75O℃煅烧2h后的样品呈明显的CaCu3Ti4O12(CCTO)类钙钛矿晶相,表明样品经历非晶相向类钙钛矿晶相转化过程.红外和拉曼谱分析进一步证实了X射线衍射结果.热分析研究结果也表明,在不到300℃,有机物燃烧完毕,随着温度的继续升高,到750℃样品开始向类钙钛矿相转化,直到1000℃完全生成了类钙钛矿晶相,经750、850、1000℃煅烧的样品其Raman光谱大致相同。 相似文献
17.
采用熔盐法制备了板状Bi4Ti3O12微晶.用示差扫描量热-热重分析(DSC-TG)、X射线衍射(XRD)及扫描电镜(SEM)研究了不同温度对合成Bi4Ti3O12相结构与形貌的影响.结果表明,板状Bi4Ti3O12微晶的最佳合成温度为800~1000℃,低于800℃合成产物中容易出现杂相;1030℃时Bi4Ti3O12出现结构变化;1165℃出现杂相Na0.5Bi0.5Ti7O27;温度继续升高到1250℃时Bi4Ti3O12出现分解.实现板状Bi4Ti3O12微晶形貌可控的最佳温度范围为850~950℃. 相似文献
18.
Ba4(Nd0.85Bi0.15)28/3Ti18O54陶瓷低温化研究 总被引:1,自引:0,他引:1
采用复合添加BaCuO2-CuO和BaO-B2O3-SiO2助剂的方法,研究了Ba4(Nd0.85Bi0.15)28/3 Ti18O54陶瓷的低温烧结特性和微波介电性能.添加2.5wt?CuO2-CuO和5wt?O-B2O3-SiO2后Ba4(Nd0.85 Bi0.15)28/3 Ti18O54陶瓷在950℃烧结成瓷,气孔率为5.29%,介电常数ε为60.25,Q·f值为2577GHz(5.6GHz),频率温度系数τf为 25.1ppm/℃,可与Cu电极浆料低温共烧. 相似文献