溶剂热电化学还原氯仿制备类金刚石碳膜的研究

报道了采用溶剂热电化学法还原氯仿制备类金刚石碳膜(DLC)的新体系. 实验在－1.2或－1.6 V (vs. Ag/AgCl/Cl^－)下, 对溶解在以Bu₄NCl作为支持电解质的碳酸丙烯酯(PC)溶液中的氯仿进行电化学还原. 研究了温度、氯仿/PC比例和电极材料对沉积的影响. 采用拉曼光谱, SEM, FTIR, XPS等方法对产物进行表征. 结果表明,在100 ℃,氯仿/PC比例为1∶3, Pt电极上沉积的DLC膜含有较高的sp³杂化态碳. 论文还提出了电化学还原氯仿沉积DLC薄膜的机理.     

用同步辐射光研究CO在Cs/Ru(100)表面的吸附

(CO+Cs)/Ru(1010)共吸附的体系中,CO分子由于受CS原子强烈影响,分子轨道发生重新杂化组合.CO分子原来在清洁Ru(1010)表面上结合能位于7.5eV处相重叠的5σ和1π轨道对应谱峰分裂为两峰,结合能分别位于6.3和7.8eV处.其中6.3eV处的谱峰来自CO分子1π轨道的一支,它显示出该分子轨道沿衬底<0001>晶向的镜面反对称性.CO分子1π轨道的另一支和5σ轨道在结合能7.8eV处相重叠.     

BCN化合物的合成与表征

以石墨和六方氮化硼(h-BN)粉为原料,利用高能机械球磨和高温高压技术对BCN化合物的形成、结构及相变进行了研究.经120h球磨制备出BCN非晶体.在1400cm^-1附近,BCN非晶有一宽化的强红外吸收峰,在740和1630cm^-1附近观察到弱的红外吸收峰;在1330cm^-1附近观察到一宽化的Raman散射峰.BCN非晶中B_1s的结合能为191.9eV,C_1s的结合能为284.9和286.8eV,N_1s的结合能为398.3和400.5eV.将BCN非晶在4GPa和1473K下退火45min后转化为六方结构的BCN晶体,其晶格常数为a=0.2505nm,c=0.6664nm.其红外光谱特征吸收峰分别出现在1398,1103,1024,925和802cm^-1.Raman散射峰分别出现在1328,1358,1582和1614cm^-1.并对非晶BCN的形成和相转变机制进行了研究.     

PCVD法制备ZrO~2和YSZ薄膜

以金属β-二酮类有机螯合物Zr(DPM)~4和Y(DPM)~3为挥发性源物质, 采用微波等离子体化学气相淀积法于较低的温度下(420～560℃)成功地在多孔α-Al~2O~3陶瓷,非晶玻璃等衬底上制备出致密的ZrO~2和YSZ薄膜材料.XRD分析结果表明,纯ZrO~2薄膜中除了单斜相外还存在着亚稳态的四方相.当掺入的Y~2O~3 摩尔百分含量大于或等于7%时,ZrO~2完全被稳定成立方相.SEM观察表明, 在等离子体内的不同区域中生成的薄膜形貌有所不同.XPS检测了YSZ薄膜中Zr3d~5~/~2和Zr3d~3~/~2 的电子结合能,发现较ZrO~2的标准值低0.7eV.由TEM观察和由XRD衍射峰半宽度计算, 所制备的ZrO~2和YSZ薄膜中微晶粒径在10nm左右     

己烯在Ru(1010)表面价带电子特性研究

在200K以下己烯(C6H12)可以在Ru(101珔0)表面上以分子状态稳定吸附.偏振角分辨紫外光电子谱(ARUPS)结果表明,己烯分子在垂直于衬底表面并沿衬底表面<12珔10>晶向的平面内,己烯分子的轴向沿<12珔10>晶向倾斜.随着衬底温度的提高,到200K以上,己烯分解生成新的碳氢化合物.己烯分解后,πCH分子轨道能级向高结合能方向移动了0.2eV,同时己烯中C的1s能级向低结合能方向移动了0.3eV.     

以Au和Au-Cu为衬底的Si/DLC薄膜的机械性能

通过纳米划痕测试技术(nano-scratch)研究了以Au和Au-Cu(xAu=93%, xCu=7%)为衬底, 多晶硅Si为基片的类金刚石(DLC)薄膜的机械性能, 其中DLC薄膜厚度约为10 nm. 研究结果表明, Au-Cu衬底对Si/DLC薄膜的结合力比Au衬底对Si/DLC薄膜的结合力要好. 紫外(244 nm)为激发光源的拉曼光谱测试结果显示在相同薄膜制备条件下Au-Cu衬底比Au衬底含有更多的sp3成分, 同时也意味着以Au-Cu为衬底的Si/DLC薄膜具有更高的硬度和密度. 通过对研究结果的分析讨论可以得出, 由于具有较好的结合力和高硬度, Au-Cu是磁记录磁头保护膜Si/DLC薄膜的更好lead材料.     

射频磁控溅射CNx薄膜的结构与衬底温度关系的研究

使用射频磁控溅射方法在不同衬底温度下（ts=室温，350，500℃）于Si(001)衬底上沉积了CNx膜，并利用拉曼（Raman)光谱、傅里叶变换红外光谱（FTIR）及X射线衍射光电子能谱（XPS）对CNx膜的化学结合状态与温度的关系进行了研究。Raman光谱结果表明，随衬底温度（ts) 增加，D带向低频方向移动，G带向高频方向移动；它们的半高宽分别由375和150cm^-1减小至328和142cm^-1；ID／IG由3．76减小至2.88。FTIR谱中除无序D带（1400cm^-1)和石墨G带（1570cm^-1)外，还有－700cm^-1,～2210cm^-1(C=N),2330cm^-1(C-O)及3255－3351cm^-1(N-H)等峰。XPS测试结果表明：随衬底温度增加，N与C的物质的量比由0.49下降至0.38，sp^2(C-N)组分与sp^3(C-N)组分强度比呈增大趋势。低温（350℃）退火并未对CNx膜的化学结合状态产生较大影响；高温（900℃）退火样品则显示出较好的结晶化程度。     

射频磁控溅射CN x薄膜的结构与衬底温度关系的研究

使用射频磁控溅射方法在不同衬底温度下(ts=室温, 350, 500 ℃)于Si(001)衬底上沉积了CN x膜, 并利用拉曼(Raman)光谱、傅里叶变换红外光谱(FTIR)及X射线衍射光电子能谱(XPS)对CN x膜的化学结合状态与温度的关系进行了研究. Raman光谱结果表明, 随衬底温度(ts)增加, D带向低频方向移动, G带向高频方向移动; 它们的半高宽分别由375和150 cm -1减小至328和142 cm -1; ID/IG由3 76减小至2 88. FTIR谱中除无序D带(1 400 cm -1)和石墨G带(1 570 cm -1)外, 还有~700 cm -1, ~2 210 cm -1(C≡N), 2 330 cm -1(C-O)及3 255~3 351 cm -1(N-H)等峰. XPS测试结果表明:随衬底温度增加, N与C的物质的量比由0 49下降至0 38, sp2(C-N)组分与sp3(C-N)组分强度比呈增大趋势. 低温(350 ℃)退火并未对CN x膜的化学结合状态产生较大影响; 高温(900 ℃)退火样品则显示出较好的结晶化程度.     

新型碳材料表面元素及化学态高分辨XPS定量研究*

X射线光电子能谱(XPS)在科学研究中被广泛应用于碳材料表面官能团识别和结构缺陷判定,对表面组成结构识别和性能调控具有重要指导意义。XPS数据分析主观性强、sp²杂化态对应C1s谱峰峰形不对称以及各化学态对应峰位差异相对较小等因素是导致碳材料XPS数据分析难度高的主要原因。本文通过对XPS分析碳材料现状总结了当前新型碳材料XPS数据分析方法的不足(主要包括■化学态对应C1s谱峰峰形不对称峰形、各化学态半峰宽拟合的随意化以及数据的主观化);并结合实际材料通过■化学态谱峰峰形参考化、半峰宽相对限定化以及多数据分析客观化对新型碳材料XPS数据方法进行进一步规范,为XPS应用于新型碳材料表面元素及化学态定量高分辨研究提供理论依据和技术保障。     

6H-SiC/3C-SiC/6H-SiC量子阱结构制备及其发光特性

利用固源分子束外延(SSMBE)生长技术, 在1350K的衬底温度下, 通过改变Si束流强度, 在6H-SiC(0001)面上外延生长6H-SiC/3C-SiC/6H-SiC量子阱结构薄膜, 并用反射高能电子衍射(RHEED)与光致发光(PL)谱对生长的薄膜的晶型和发光特性进行表征. RHEED 结果显示生长的薄膜为6H-SiC/3C-SiC/6H-SiC量子阱结构薄膜. 室温下He-Gd激光激发的光致发光(PL)谱显示, 薄膜在480-600 nm范围内存在衬底未观察到的较强发光. 拟合得到的发光峰与依据量子阱结构模型计算出的发光位置较为一致. 由此表明, 该强发光带可能是6H-SiC/3C-SiC/6H-SiC量子阱结构的发光.     

Nitrogen-doped diamond-like carbon as optically transparent electrode for infrared attenuated total reflection spectroelectrochemistry

This contribution describes the development of nitrogen-doped diamond-like carbon (N-DLC) thin films for multi-reflection mid-infrared (MIR) attenuated total reflectance (IR-ATR) spectroelectrochemistry. N-DLC coatings were deposited using pulsed laser deposition (PLD) involving the ablation of a high purity graphite target. The DLC matrix was further modified by ablating the target in the presence of nitrogen gas. This technique offers the advantage of depositing thin films at room temperature, thereby enabling coating of temperature-sensitive substrates including e.g., MIR waveguides. The resulting films were analyzed with X-ray photoelectron spectroscopy (XPS), and determined to be composed of carbon, nitrogen, and adventitious oxygen. Raman spectroscopic studies indicate that the addition of nitrogen induces further clustering and ordering of the sp(2)-hybridized carbon phase. The electrochemical activity of PLD fabricated N-DLC films was verified using the Ru(NH(3))(3+/2+) redox couple, and was determined to be comparable with that of other carbon-based electrodes. In situ spectroelectrochemical studies involving N-DLC coated zinc selenide (ZnSe) MIR waveguides provided evidence concerning the oxidation of N-DLC at anodic potentials in 1 M HClO(4) solutions. Finally, the electropolymerization of polyaniline (PAni) was performed at N-DLC-modified waveguide surfaces, which enabled spectroscopic monitoring of the electropolymerization, as well as in situ studying the structural conversion of PAni at different potentials.     

ZnO thin films prepared on titanium substrate by PLD technique at different substrate temperatures

ZnO thin films were grown by pulsed laser deposition on titanium substrates at different substrate temperatures ranging from 300 to 700 °C. X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS),photoluminescence, and Raman spectroscopy are employed to investigate the change of properties. XRD, XPS, and Raman data showed that the films consisted of TiO₂ at high substrate temperature, which will deteriorate the crystallization quality of ZnO films. The optimum temperature for the growth of ZnO films on the Ti substrate is about 500 °C in this paper. The ZnO films grown on titanium substrate can be used in direct current, microwave, and medical applications. Copyright © 2014 John Wiley & Sons, Ltd.     

Deposition of Diamond-like Carbon Films using Graphite Sputtering in Neon Dense Plasma

This paper reports the deposition of diamond-like carbon (DLC) films on Si <100>, using a low energy (1.45 kJ) dense plasma focus assisted sputtering of graphite insert at the tip of the tapered anode. The substrates are placed in front of the anode at different axial and angular positions and are exposed to multiple focus shots. The information regarding the DLC structure is acquired by using Raman spectroscopy. The spectra are characterized by two broad bands known as “G-band” and “D-band”. The results point towards the formation of DLC films with both sp³ (diamond like) and sp² (graphite like) domains. In X-ray diffraction (XRD) pattern, no additional peak is observed except a peak at 2θ = 69° which corresponds to the silicon (Si) substrate. The intensity of Si peak is reduced after treatment indicating the deposition of amorphous carbon. Scanning electron microscopy (SEM) results demonstrate that the smoothness of the film increases with increasing the substrate angular positions with respect to the anode axis. Energy dispersive X-ray (EDX) analysis reveals that the films deposited at lower axial and angular positions are thicker which is complemented by the cross-sectional views of the films.     

Growth and characterization of ultrathin carbon films on electrodeposited Cu and Ni

Ultrathin carbon films were grown on different types of metallic substrates. Free‐standing foils of Cu and Ni were prepared by electroforming, and a pure Ni film was obtained by galvanic displacement on a Si wafer. Commercial foil of Ni 99.95% was used as a reference substrate. Carbon films were grown on these substrates by chemical vapour deposition in a CH₄‐H₂ atmosphere. Obtained films were characterized by Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, and ultraviolet photoemission spectroscopy. The XPS at grazing collection angle was used to determine the thickness of carbon films. Depending on the deposition parameters, the films of graphene or graphite were obtained on the different substrates. The uniformity of graphene and its distribution over the sample area were investigated from Raman data, optical images, and XPS chemical maps. The presence of graphene or graphite in the films was determined from the Raman spectra and Auger peak of C KVV. For this purpose, the D parameter, which is a fingerprint of carbon allotropes, was determined from C KVV spectra acquired by using X‐rays and electron beam. A formation of an intermediate layer of metal hydroxide was revealed in the samples with graphene overlayer.     

轰击离子能量对CNx薄膜中sp3型C-N键含量的影响

对磁控溅射生长在单晶Si(001)衬底上的CNx薄膜样品的化学键合及结构进行了研究,利用不同的衬底负偏压(Vh)来控制轰击衬底表面的入射离子能量,从而影响膜中的化学键合的状态.样品的FTIR,Ra-man和XPS分析结果表明,CNx薄膜中N原子分别与sp,sp2和sp3杂化状态的C原子结合,其中sp3型C-N键含量先随着衬底偏压(Vb)的升高而增加,并在偏压Vb=-50V时达到最大值,但随着Vb继续升高,sp3型C-N键含量减少,这表明CNx薄膜中,sp3型C-N键的含量与轰击离子的能量变化密切相关.     

Raman characterization of amorphous carbon films

Amorphous carbon films, deposited with the LASER-ARC technique, have been characterized using Raman scattering experiments at an excitation wavelength of 633 nm provided by a He-Ne laser. To distinguish between the homogeneous amorphous film and incorporated particles area resolved measurements have been carried out due to the laser spot diameter of 1 m. Typical diamondlike (DLC) films, grown near room temperature, show a broad Raman band between 1000 cm^–1 and 1800 cm^–1 fitted very well by two gaussian distributions. Films deposited at higher substrate temperatures reveal more graphitic features in the spectra. The spectra of particles consists of a graphite-like portion originated from the graphitic structure of the particle and a diamond-like portion caused by the covering DLC film. The degree of disorder and diamond-likeness in the film structure is quantified by the peak position, the full width at half maximum (FWHM) and intensity relation of the fitted D- and G-peaks.     

The effect of different substrate temperatures on the structure and luminescence properties of Y2O3:Bi3+ thin films

Y₂O₃:Bi³⁺ phosphor thin films were prepared by pulsed laser deposition in the presence of oxygen (O₂) gas. The microstructure and photoluminescence (PL) of these films were found to be highly dependent on the substrate temperature. X-ray diffraction analysis showed that the Y₂O₃:Bi³⁺ films transformed from amorphous to cubic and monoclinic phases when the substrate temperature was increased up to 600 °C. At the higher substrate temperature of 600 °C, the cubic phase became dominant. The crystallinity of the thin films, therefore, increased with increasing substrate temperatures. Surface morphology results obtained by atomic force microscopy showed a decrease in the surface roughness with an increase in substrate temperature. The increase in the PL intensities was attributed to the crystallinity improvement and surface roughness decrease. The main PL emission peak position of the thin films prepared at substrate temperatures of 450 °C and 600 °C showed a shift to shorter wavelengths of 460 and 480 nm respectively, if compared to the main PL peak position of the powder at 495 nm. The shift was attributed to a different Bi³⁺ ion environment in the monoclinic and cubic phases.     

用XPS和XAES分析电化学沉积的DLC膜

采用电化学沉积方法，以甲醇溶剂作碳源，直流电压作用下在单晶硅表面沉积得到碳薄膜。通过研究石墨、金刚石和样品薄膜的XPS和XAES谱图特征，证明了此方法沉积得到的是DLC薄膜;利用曲线拟合技术在C_1s电子能谱图中拟合出sp³峰与sp²峰，并计算出样品薄膜中sp³碳的相对含量为55%;研究石墨、金刚石和样品薄膜的一阶微分XAES谱图，用线性插入法估算出样品薄膜中sp³碳的相对含量为60%。     

The chemical composition and bonding structure of amorphous hydrogenated carbon nitride film on aluminum surface deposited by electrodeposition

Amorphous hydrogenated carbon nitride films with excellent adhesion to the substrates were deposited on the surfaces of aluminum plates by electrodeposition with acetonitrile as carbon source. The as‐obtained films were detailed characterized by Raman, XPS and FTIR. The results show that the as‐obtained films are mainly made up of sp2 C, sp3 C, C? N, C?N bonds and a spot of sp3? CH₂, sp3? CH₃, sp3? CH and sp2? CH bonds. The atomic ratio of N/C is evaluated to be about 2.98 at.% by XPS. Raman analysis indicated that I_D/I_G ratios decreased from 0.827 to 0.675 when the deposition time increased from 10 to 20 h. At the end, on the basis of the detailed analysis, results of Raman, FTIR and XPS, the possible deposition mechanism was discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Diamond-like carbon coatings with Ca-O-incorporation for improved biological acceptance

Diamond-like carbon (DLC) coatings were modified by doping the thin films with Ca-O compounds. Raman spectroscopy indicates growth of sp(2)-hybridised, ordered regions in size and/or number within the amorphous carbon-hydrogen network as a result of the Ca-O-incorporation. CaCO(3) was identified by X-ray induced photoelectron spectroscopy. Proliferation and morphology of L929 mouse fibroblasts reveal improved biocompatibility of Ca-O-modified DLC.