聚三甲硅基丙炔膜表面改性的XPS研究——Ⅰ.用N-溴代丁二酰亚胺的表面改性

用N-溴代丁二酰亚胺的丙酮溶液在回流温度下对三甲硅基丙炔的均聚物和共聚物作了表面改性。XPS的研究表明,试样表面层中Br原子含量随溴化时间的增长而增加,C_(IS)谱变宽且产生来自C-O和C-Br结构的新谱线。红外光谱证明溴化反应产生CH_2Br结构。溴化使膜的气透性发生相应的变化,即α_(O_2/N_2)值增高,P_(O_2)值降低。

电子束法沉积ZnIn_2Se_4膜的结构与XPS表征

研究了电子束法沉积ZnIn_2Se_4薄膜的工艺条件,所得致密、均匀膜的导电类型可以通过不同气氛处理得到控制。该膜的最佳参数为:电阻率ρ为2.35×10~(-1)Ω·cm,Hall迁移率μ_H为106cm~2·V~(-1)·S~(-1),载流子浓度N是1.51×10~(17)cm~(-3),禁带宽度E_(?)为2.23eV。采用XPS技术研究了膜的组成、结构、价态。

LnBa_2C_3O_(7-δ)(Ln=Pr、Y)体系的XPS研究

该文研究了YBa_2Cu_3O_(7-δ)和PrBa_2Cu_3O_(7-δ)两体系的XPS谱图,结果表明从XPS图中难以判断三价铜的存在,与YBa_2Cu_3O_(7-δ)体系相比,PrBa_2Cu_3O_(7-δ)体系中Ba的结合能低,O_(18)的两个状态变得模糊不清。讨论了空穴浓度对高T_c超导电性的影响。

LaMn_(1-x)Co_xO_(3-λ)催化剂的XPS研究

用柠檬酸络合法制备了LaMn_(1-x)Co_xO_(3-λ)系列稀土复合氧化物。用XPS技术研究了它的表面、体内组态和结构变化及锰和钴含量对La 3d_(5/2)特征峰和Shske-up伴峰的影响。认为α-O是催化剂中的活性氧种。用氩离子剥离技术研究了LaMn_(1-x)Co_xO_(3-λ)体系,观察到锰在表面的偏析作用随x的减小而增大。

EVALUATION OF THE EFFECT OF WAVELENGTH POSITIONING ERRORS ON KALMAN FILTERING RESULTS IN INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

This work evaluates the effect of wavelength positioning errors in spectral scans on analytical results when the Kalman filtering technique is used for the correction of line interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES). The results show that a positioning accuracy of 0.1 pm is required in order to obtain accurate and precise estimates for analyte concentrations. The positioning error in sample scans is more crucial than that in model scans. The relative bias in measured analyte concentration originating from a positioning error in a sample scan increases linearly with an increase in the magnitude of the error and the peak distance of the overlapping lines, but is inversely proportional to the signal-to-background ratio. By the use of an optimization procedure for the positions of scans with the innovations number as the criterion, the wavelength positioning error can be reduced and, correspondingly, the accuracy and precision of analytical results improved.

PREPARATION, STRUCTURE AND INFLUENCE OF VALENCE STATE ON LASR2-XCAXV3O9+/-Y

New compounds LaSr2-xCa-(x)V3O9+/-y (x = 0.0, 0.67, 1.0, 1.33 and 2.0) have been synthesized with a simple new method X ray powder diffraction results indicate that they are single compound. Their lattice constants are calculated. The structure of LaSr2-xCa(x)V39+/-y changed from cubic to orthorhombic and back to cubic with the increase of calcium content. The results of weight gain in TG and XPS curves show that vanadium with lower valent state is oxidized to higher valent state at higher temperature. The oxygen content of new compounds are calculated from the weight gain. It is shown that V3+ and V4+ may coexist in LaSr2-xCa(x)V3O9+/-y. These compounds show that low resistivity.

COORDINATION CHEMISTRY AND SUPERCONDUCTIVITY

Analysing the coordination state of copper ions in cuprate superconductors, it is found that the larger the energy splitting between d(x2-y2) and d(z2) orbitals of Cu or the higher the energy of the d(x2-y2) orbital, the higher the Tc. Thus, appropriate coordination structures and strong-field ligands must be chosen for expanding the energy splitting and increasing the energy of the d(x2-y2) orbital when searching for new high-Tc superconductors. Summarizing the experimental results of ESR and XPS, it is considered that the [Cu2+ - O open-square-box 2- - Cu3+] resonance exists in cuprate superconductors and the electron field breathing mode is present. Analysing the mechanism and the relationship between the coordination state of Cu and Tc, we consider that the two dimensional Cu-O planes are responsible for the superconductivity of YBa2Cu3O7-y.

WATER-SOLUBLE AND AMPHIPHILIC POLYMERS .6. A STUDY ON THE SURFACE-COMPOSITION OF CAST FILMS OF PST/PMAA AND PEO-PST-PEO BLOCK POLYMERS BY XPS

Thin films of PSt/PMAA and PEO-PSt-PEO block polymers were deposited on a polystyrene substrate by solution adsorption (with or without solvent treatment), and the film surfaces were characterized by means of XPS. Direct solvent - casting of PEO-PSt-PEO from benzene solutions resulted in PSt-rich surfaces, whereas PMAA richer surfaces were obtained for PSt/PMAA films cast from DMF solutions. Moreover, solvent treatment after casting had profound effect on the film surface composition. Treatment with water markedly increased the surface concentration of polar PEO segments. In the case of PSt-PMAA block polymers, the PSt content on the surface increased in the order of water < ethanol < cyclohexane < petroleum ether, the last-named giving films with almost pure PSt surface. It is well worth noticing that the bulk composition had little to do with the surface composition for both PSt/PMAA and PEO-PSt-PEO block polymers within the composition range investigated when subsequent solvent treatment was applied.

XPS研究等离子体处理的聚苯乙烯表面结构

采用不同功率(10、20、60、100、150W)、时间(0.5、1、3、6、15和30分),在Ar、N_2、O_2、H_2和空气中,对聚苯乙烯(PS)片基进行了等离子体处理。 通过XPS技术、谱图的拟合、差谱分析和Ar~+小功率剖面处理,研究了PS表面组成与结构变化,指出处理的聚苯乙烯表面有C—O、C—NH_2、C=O、COOH和基团嵌入,因而改变了材料特性。

用XPS振起伴峰表征聚苯醚酮的辐射凝胶化剂量

X-射线光电子能谱(XPS)振起(Shake-Up)伴峰主要是伴随主光电子的电离所导致的最高占有轨道到最低未占有轨道电子跃迁的结果.Carlson及Clark的工作声明这种振起伴峰是某些共轭π电子体系的表征,振起伴峰的相对强度与π电子共轭情况有关。 含酚酞侧基聚芳醚酮(PEK-C)是一种新型耐高温工程塑料,其主侧链均带苯环:

PMo_(12-x)V_x和PMo_(12-x)W_x杂多酸的XPS研究 Ⅰ.杂多酸中氧的俄歇谱

用XPS对杂多酸PMo_(12-x) V_x和PMo_(12-x) W_x的研究表明:在用V部分取代Mo时,虽然O1s峰没有给出什么有意义的结构信息,但OKL_(23)L_(23)俄歇跃迁动能随X增大而增大;在W部分取代Mo时,OKL_(23)L_(23)俄歇峰的动能随X增大而减少。杂多酸中酸性与OKL_(23)L_(23)数值有一定的关系。从OKL_1L_1与OKL_(23)L_(23)俄歇峰强度之比,求出氧成键时增加电荷,进一步表明了杂多酸中氧原子成键情况。

杂多酸PMo_(12-x)V_x和PMo_(12-x)W_x的XPS研究 Ⅱ.氧的双电离能及轫致辐射诱导的磷、钼俄歇谱

利用式E_Ⅱ(min)=E_B(K)-E_i(L_(23)~+L_(23)~+)可以从OKL_(23)L_(23)价态型俄歇跃迁能量求出氧的双电离能,它与杂多酸的Bronsted质子酸有一定的对应关系。本文利用铝靶的轫致辐射诱导MoL_3M_(45)M_(45)和PKL_(23)L_(23)俄歇跃迁,实现了在一个阳极和同一次实验情况下,既测得Mo、P特征的电光电子峰,又记录了高动能的俄歇峰。Mo、P的俄歇谱可表明杂原子与杂多配位原子的关系。

用XPS振起伴峰估算含酚酞侧基聚芳醚砜的辐射凝胶化剂量

含酚酞侧基聚芳醚砜(PES—C)是近年来陈天禄等刚刚开发出的一种新型耐高温高分子材料,其结构为:

SURFACE CHARACTERIZATION OF COBALT TETRAPHENYLPORPHYRIN MODIFIED GLASSY CARBON ELECTRODE BY XPS

Surface structure of the glassy carbon surface modified with cobalt tetraphenyl-porphyrin (CoTPP) by thermal-treatment has been studied by XPS, DTA and TG. During the thermal treatment a bond can be formed between the glassy carbon surface and TPP. Therefore the stability of electrode for the catalysis of dioxygen reduction is improved. Upon thermal treatment at 600 degrees C, FWHM of Co(2p(2/2)) is broadened, the reason is due to overlapping of peaks of multiple states, the spin orbit separation between Co (2p(1/2)) and Co (2p(3/2)) increases to 15.5-16.3eV, which indicated a change from low spin divalent states, the kinetic energy of Co L3VV Auger line and Auger parameter also increase. These changes of central cobalt ion provide a suitable redox potential for Co(III)/Co(II) which is related to the activity for catalysis of dioxygen reduction.

La_(1-x)Sr_xCoO_3的XPS研究 Ⅳ.La_(1-x)Sr_xCoO_3的价态谱

钙钛矿ABO_3复合氧化物用于取代贵金属催化剂的研究工作已取得突破性进展尤其是近几年来在具有钙钛矿结构类型化合物中高临界温度超导材料的发现,更引起国内外学者的重视。对LaCoO_3的结构及各种物化性质的研究已相当多。Lam等用XPS对LaCoO_3一类化合物的价带谱进行过研究,并且与用分子簇、自由离子模型的计算结果进行比较,解释了LaCoO_3的电子结构。我们曾对La_(1-x)Sr_xCoO_3中La与配位体之间的作用,表面氧的状态以及在氢气气氛下钴的还原行为作过研究,但至今对