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采用直流磁控溅射法在P型<100>晶向单晶硅衬底上室温制备ZnO薄膜,对室温制备的ZnO薄膜分别在500℃、600℃、700℃进行高温退火,通过采用X射线衍射(XRD)、拉曼光谱和场发射扫描电子显微镜(SEM)、HP4145B型半导体参数测试仪分析不同退火温度对室温生长ZnO薄膜微结构、表面形貌和,Ⅰ-Ⅴ特性影响.实验结果表明,室温生长的ZnO薄膜为非晶态,随退火温度增加,ZnO薄膜出现(002)、(100)、(101)晶面衍射峰且逐渐增强,晶粒大小相对增加,在700℃退火后,呈高度c轴择优取向,晶粒间界明显,拉曼光谱E2模增强. 相似文献
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以乙二醇甲醚为溶剂,采用溶液法成功制备了致密的、铁电相和铁磁相共存的0-3型磁电复合薄膜.采用X射线衍射(XRD)、原子力显微镜(AFM)、X射线能潜分析(EDAX)、压电响应力显微镜(PFM)分析了退火时间对两相结构、晶粒大小、薄膜形貌、电畴及磁畴的影响.结果表明,退火20 min 对于 PbTiO3相晶粒的生长已经足够,随着退火时间的延长,CoFe2O4相的品粒逐渐长大,薄膜的均方根粗糙度有所提高;同时因为磁件相品粒的长大复合薄膜电畴的取向发生了极大地变化.复合薄膜中同时存在的电畴和磁畴证明了其同时具有的铁电性和磁性. 相似文献
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用快速光热退火制备多晶硅薄膜的研究 总被引:10,自引:3,他引:7
用等离子体增强型化学气相沉积先得到非晶硅(a-Si:H)薄膜,再用卤钨灯照射的方法对其进行快速光热退火(RPTA),得到了多晶硅薄膜.然后,进行XRD衍射谱、暗电导率和拉曼光谱等的测量.结果发现,a-Si:H薄膜在RPTA退火中,退火温度在750℃以上,晶化时间需要2min,退火温度在650℃以下,晶化时间则需要2.5h;晶化后,晶粒的优先取向是(111)晶向;退火温度850℃时,得到的晶粒最大,暗电导率也最大;退火温度越高,晶化程度越好;退火时间越长,晶粒尺寸越大;光子激励在RPTA退火中起着重要作用. 相似文献
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脉冲退火法制备多晶硅薄膜的研究 总被引:1,自引:1,他引:0
用射频等离子体化学气相沉积(RF-PECVD)法在普通玻璃衬底上低温制备了μc-Si:H薄膜.采用快速光热退火炉(RTP),分别用低温(<650℃)和中温(<750℃)脉冲法(PRTP)对薄膜进行了退火处理.用拉曼光谱和扫描电子显微镜(SEM)研究了不同条件下退火薄膜散射谱的特征和表面形貌.结果显示,脉冲退火法晶化的薄膜,晶化率达到了53;,部分颗粒团簇的尺寸已达到200nm左右.用声子限域理论和表面尺寸效应对薄膜频谱的"红移"和"蓝移"现象进行了分析. 相似文献
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以氧化镁和二氧化硅为原料,采用水热法在不同反应时间下合成了一系列纤蛇纹石纳米管.利用X-射线衍射(XRD)、红外光谱(IR)、扫描电镜(SEM)、高分辨透射电镜(TEM)等手段研究了纤蛇纹石晶体生长和晶体结构随反应时间的变化过程.X-射线衍射和红外光谱分析表明:随着反应时间的增加所得到的纤蛇纹石样品结晶逐渐完善、卷曲程度逐渐增大;电镜分析表明:获得的纳米管的外径和内径分别为15~40 nm和6~9 nm,长度为50~300 nm,出现了双层管式结构.根据实验结果,结合负离子多面体配位生长理论对纤蛇纹石的生长机理研究表明,纤蛇纹石是由片状逐渐卷曲成管状的. 相似文献
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Prakash S. Nayak Sumati Anthal Vivek K. Gupta Rajni Kant H. S. Yathirajan 《Molecular Crystals and Liquid Crystals》2014,592(1):249-258
4-[(3-Acetylphenyl)amino]-2-methylidene-4-oxobutanoic acid (1) is synthesized by a ring opening reaction of itaconic anhydride with 3-aminoacetophenone and characterized by FT-IR, 1H NMR, UV-Vis, TGA, DTA, and single crystal X-ray diffraction. The crystal of 1 belongs to triclinic unit cell in the P-1 space group with the unit cell dimensions a = 4.9485(3), b = 5.3614(6), c = 22.457(2) Å, α = 88.295(8), β = 89.379(7), γ = 84.495(7), and Z = 2 The crystal structure is solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.0467 for 1623 observed reflections. Intermolecular N&;sbnd;H?…O and O&;sbnd;H?…O hydrogen bonds links the molecules into chains along [010] direction. In addition the thermal stability of the 1 is determined by using DTA, TGA analysis, and wavelength absorption at λmax = 297 nm is determined by UV-Vis spectrophotometer. 相似文献
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Zinc sulfide (ZnS) microspheres were synthesized by a self‐template hydrothermal route using thiourea as sulphur source. The formation of these hollow spheres was mainly attributed to the oriented aggregation of ZnS nanocystals around the gas‐liquid interface between gas (H2S, NH3, or CO2) and water followed by an Ostwald ripening process. The gas bubbles of H2S, NH3, or CO2 produced during the reaction might play a soft‐template to form ZnS hollow microspheres. The products were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), electron diffraction (ED), and photoluminescence (PL). The crystal structure of prepared ZnS microspheres is hexagonal phase polycrystalline. The average microspheres diameter is 1.5 ‐ 6 µm. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Crystallography Reports - It is shown by the example of hydrogen (in hydrides ZrH), helium (in pores after implantation), and nickel (in G-phase precipitates) that the application of electron... 相似文献
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P. Gluziński R. A. Koliński Z. Urbańczyk-Lipkowska J. W. Krajewski 《Journal of chemical crystallography》1992,22(1):31-36
The copper(II) dinitrate complex of the title heteromacrocycle has been investigated by X-ray diffraction. The structure was solved by direct methods and refined by a full-matrix least-squares, givingR=0.0318 with 1778 unique reflections. The Cu(II) cation is coordinated inside the N(7), N(13)-folded macrocycle. The coordination sphere of Cu(II) is a distorted square pyramid with N(7), O(10), N(13) of the macrocycle and O(1a) of the nitrate anion atoms occupying the corners of the base of the pyramid and the O(1) macrocycle atom in the apical position. The other nitrate group was found in a remote position with respect to the Cu(II) cation. 相似文献
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R. Vijaya Kumar R. Elgamiel Yu. Koltypin Jochen Norwig A. Gedanken 《Journal of Crystal Growth》2003,250(3-4):409-417
Micro scale zinc oxide-polyvinyl alcohol (ZnO–PVA) composite has been synthesized by ultrasound irradiation. The properties of the as-prepared ZnO–PVA composite material are characterized by X-ray diffraction (XRD), thermo gravimetric analysis (TGA), transmission electron microscopy (TEM), and diffuse reflection spectroscopy (DRS). A band gap of 3.25 eV is estimated from DRS measurements. The controlled crystal growth of zinc oxide has been studied by using the as-prepared micro scale ZnO–PVA composite as seeds for the crystal growth of ZnO. 相似文献
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通过溶剂热反应合成了Fe3O4空心微球.采用X射线衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)对样品的结构和形貌进行了表征.结果表明,所制备的单分散Fe3O4空心微球为立方多晶结构,其直径约400 nm,是由约40 nm纳米颗粒组装而成.用振动样品磁强计(VSM)测量了Fe3O4空心微球的室温和变温磁性.室温磁滞回线表明不同反应时间所得产物均表现为良好的亚铁磁性,其饱和磁化强度Ms随反应时间的增加先升后降.由反应时间为12 h所得的Fe3O4空心微球在1000 Oe下的M-T曲线测得其居里温度为778 K,并测得其在外磁场H=5000 Oe场冷却至液氮温度再升至不同温度(100 K,200 K,300 K)时的磁滞回线,发现不同温度时测得的Fe3O4空心微球磁滞回线都是左右对称的,没有明显的交换偏置效应,且随测量温度增加,其饱和磁化强度Ms和矫顽力Hc均降低. 相似文献
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The incorporation of an additive during sol-gel synthesis reduces shinkage during ambient drying. The following additives have been studied: 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS), 3-aminopropyltriethoxysilane (AES) and 3-(2-aminoethylamino)propyltriethoxysilane (EDAES) and the main silica precursors were tetraethylorthosilicate (TEOS) and tetrapropylorthosilicate (TPOS). When the additive contains methoxy groups (EDAS), it acts as a nucleation agent of the silica particles and exactly the same properties (pore volume, specific surface area, particle and aggregate size) are obtained whether the main reagent is TEOS or TPOS. The nucleation mechanism is based on the difference in reactivity between additive and main reagent. In case of nucleation by the additive, the nucleation agent fixes the properties whatever the main silica precursor is. When both the additive and the main reagent contain ethoxy groups (series AES-TEOS and EDAES-TEOS), there is no nucleation mechanism by the additive, and the silica particle size remains nearly constant. With less reactive main reagent (series AES-TPOS and EDAES-TPOS), pore volumes up to 17 cm3/g have been obtained with pore sizes up to nearly 10 μm and very big particles (∼100 nm). The absence of nucleation by the additive for the couples AES-TPOS and EDAES-TPOS could be due to the fact that the difference in reactivity between ethoxy groups and propoxy groups is not sufficient to initiate the nucleation mechanism by the additive. In the absence of nucleation by the additive, the main reagent plays a role: highly porous materials with very large pores are prepared with TPOS. 相似文献
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4个单核配位化合物,[Zn(Maape)2(H2O)2(NO3)2] (1, 单核), [Cu(Maape)2(H2O)2(NO3)2] (2, 单核), [Zn(Maape)2Cl2] (3, 单核), [Zn(Maape)(H2O)4SO4] (4, 单核),都是用过渡金属盐和配体2-甲基-丙烯酸,4-(吡啶-4-偶氮)-苯酯合成的.四个化合物由单晶X-射线衍射和结构分析表明都是单核化合物.另外,还通过红外和元素分析对其进行表征.配位化合物的结构不仅受配位金属离子的影响还受不同配位阴离子的影响.化合物1和2的结构都是由一个金属离子中心、2个配位硝酸根离子和2个配体分子组成的单核配合物.化合物3的单核结构中包含一个Zn(II)、2个氯离子和2个配体分子.而化合物4的不对称单元[Zn(Maape)(H2O)4SO4]中Zn(II)中心位于二重对称轴上.在本文中,配体和4个化合物都在323 nm处有最高紫外吸收峰. 相似文献
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Large‐scale zinc oxide (ZnO) nanotetrapods have been grown on p‐type Si (111) substrate by oxidizing zinc pieces in air by thermal evaporation technique without the presence of any catalyst. The size and morphology of the nanostructures was found to depend on experimental parameters. The grown nanostructures were characterized by X‐ray Diffraction (XRD), Photoluminescence (PL), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), High Resolution TEM (HRTEM) and analysis of elemental composition was done by Energy Dispersive X‐ray analysis (EDX). The EDX spectrum shows that the grown product contains Zn and O only. The X‐ray diffraction pattern indicates that the microstructure of the obtained products is typical hexagonal wurtzite ZnO. The optical properties were studied using room temperature PL spectroscopy which indicates that the products are of high optical quality and the near band edge UV transition peak intensity increases with decrease in tetrapod size. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献