X-ray photoelectron spectrometer

Some X-ray photoelectron spectrometers are equipped with monochromators that can be used to remove unwanted radiation, such as the continuous radiation and even some of the weaker characteristic X-rays such as K<,3, K 4, Kas, and Ko,6, from the emission spectrum of the anode. A monochromator can also be used to resolve the K i,2 line into its two components K i and Ka2- Using a monochromator has at least two beneficial effects. It enables the narrow, intense K<, line to be used to excite spectra at very high resolution. A monochromator also prevents unnecessary radiation (continuous, K<,2, Ka3, K<,4, Kas, and Ka6) that might contribute to thermal or photochemical degradation from impinging on the sample. 

The Fe-B nanocomposite was synthesized by the so-called pillaring technique using layered bentonite clay as the starting material. The detailed procedures were described in our previous study [4]. X-ray diffraction (XRD) analysis revealed that the Fe-B nanocomposite mainly consists of Fc203 (hematite) and Si02 (quartz). The bulk Fe concentration of the Fe-B nanocomposite measured by a JOEL X-ray Reflective Fluorescence spectrometer (Model JSX 3201Z) is 31.8%. The Fe surface atomic concentration of Fe-B nanocomposite determined by an X-ray photoelectron spectrometer (Model PHI5600) is 12.25 (at%). The BET specific surface area is 280 m /g. The particle size determined by a transmission electron microscope (JOEL 2010) is from 20 to 200 nm. 

TEM observation and elemental analysis of the catalysts were performed by means of a transmission electron microscope (JEOL, JEM-201 OF) with energy dispersion spectrometer (EDS). The surface property of catalysts was analyzed by an X-ray photoelectron spectrometer (JEOL, JPS-90SX) using an A1 Ka radiation (1486.6 eV, 120 W). Carbon Is peak at binding energy of 284.6 eV due to adventitious carbon was used as an internal reference. Temperature programmed oxidation (TPO) with 5 vol.% 02/He was also performed on the catalyst after reaction, and the consumption of O2 was detected by thermal conductivity detector. The temperature was ramped at 10 K min to 1273 K. 

We acknowledge financial support of this work by the Gas Research Institute (Contract No. 5982-260-0756). NSF support of the x-ray photoelectron spectrometer by an equipment grant, CHE-8201179, Is also acknowledged. 

Analytical Techniques. Sessile drop contact angles were measured with a NRL C.A. Goniometer (Rame -Hart, Inc.) using triply distilled water. The contact angles reported are averages of 2-8 identically treated samples with at least three measurements taken on each sample. ESCA spectra were obtained on a Kratos ES-300 X-ray Photoelectron Spectrometer under the control of a DS-300 Data System. Peak area measurements and band resolutions were performed with a DuPont 310 Curve Resolver. 

The area of complex condensed matter depends crucially on the availability of appropriate tools for both fabrication and characterization. These tools are of intermediate size they are neither a test tube nor a synchrotron. Typical tools— scanning probe microscopes, x-ray photoelectron spectrometers, electron microscopes, clean rooms—cost from 0.1 million to 5 million. They are shared-use facilities, but they must be local to the user group—travel to distance facilities for routine measurements is not practical. 

Subsequently, Grunthaner reexamined the ESCA spectrum of the 2-norbornyl cation on a higher-resolution X-ray photoelectron spectrometer using highly efficient vacuum techniques.884 The spectrum closely matches the previously published spectra. Furthermore, the reported ESCA spectral results are consistent with the theoretical studies of Allen and co-workers885 on the classical and nonclassical norbomyl cation at the STO-3G and STO-4.31G levels. Using the parameters obtained by Allen and co-workers, Clark and co-workers were able to carry out a detailed... 

Figure 3 shows the absolute Cls signal intensity derived from a homogeneous polymer film as a function of the electron take-off angle, 0, in an AEI ES 200B X-ray photoelectron spectrometer (4). For this spectrometer the angle between the X-ray source and analyzer, i ) is fixed at 90. It is clear from Figure 2 that if the sample is turned to face away from either the X-ray... 

The compositions of the products were determined by inductively coupled plasma (ICP) with a Perkin-Elmer plasma 40 emission spectrometer. Simultaneous differential thermal analysis and thermogravimetric (DTA-TG) curves were carried out by using Perkin-Elmer DTA-7000, TGA-7 PC series thermal analysis instrument in air with a heating rate of 10 °C /min. The infrared (IR) spectra were recorded on an Impact 410 IR spectrometer on samples pelletized with KBr powder. Valence states were determined by X-ray photoelectron spectroscopy (XPS). The XPS for powder samples fixed on double sided tapes was measured on an ESCA-LAB MKII X-ray photoelectron spectrometer. The Cis signal was used to correct the charge effects. 

The experiments were performed in two different ultra high vacuum (UHV) chambers using two different Pt(lll) single crystals. The X-ray photoelectron spectra were obtained in a chamber with a base pressure of lxlO" Torr. The system has been described in detail elsewhere. In brief, the UHV chamber is equipped with low energy electron diffraction (LEED), an X-ray photoelectron spectrometer (XPS), a quadrupole mass spectrometer (QMS) for temperature programmed desorption (TPD), and a Fourier transform infrared spectrometer (FTIR) for reflection absorption infrared spectroscopy (RAIRS). All RAIRS and TPD experiments were performed in a second chamber with a base pressure of 2 X 10 ° Torr. The system has been described in detail elsewhere. In brief, the UHV chamber is equipped for LEED, Auger electron spectroscopy (AES) and TPD experiments with a QMS. The chamber is coupled to a commercial FTIR spectrometer, a Bruker IFS 66v/S. To achieve maximum sensitivity, an... 

The surfaces of ACFs were analyzed using a VG Scientific LAB MK-Il X-ray photoelectron spectrometer (XPS). The spectra were collected using a MgK X-ray source (I2S3.6 eV). The pressure inside the chamber was held below SxlO torr during analysis. Both survey XPS spectra are recorded at a 45 ° take-off angle. 

Introduction of CFx thin film on top of the ITO anode as HTL via plasma polymerization of CHF3 can also enhance device performance of PFO-based PLED, as reported by us [79]. At the optimal C/F atom ratio using the radio frequency power 35 W (see Table 2) as determined by X-ray photoelectron spectrometer, the device performance based on the ITO/CFx(35 W)/PFO/CsF/Ca/Al configuration is optimal having maximum current efficiency of 3.1 cdA 1 and maximum brightness of8400 cdm 2 much better than 1.3 cd A-1 and 1800 cd m-2 for the device with PEDOT PSS as HTL. The improved device performance was attributed to a better balance between hole and electron fluxes because the CFx (35 W) layer possesses an Ip value of 5.6 eV (see Table 2), as determined by ultraviolet photoelectron spectroscopy data, and therefore causes a lower hole-injection barrier to the PFO layer (0.2 eV) than that of 0.7 eV for PEDOT PSS. 

Physical Electronics Model 548 X-Ray Photoelectron Spectrometer with... 

X-ray photoelectron spectroscopic (XPS) studies were conducted using a Surface Science Laboratories X-ray photoelectron spectrometer. Wavelength-dispersive electron microprobe results were obtained by Mr. John Donovan at the Department of Geology microanalytical facility at UC Berkeley. 

FIGURE 10.6 UETV, electrochemical device C, electrochemical cell, with sample SC, auxiliary and reference electrodes E, electrolyte AI, argon inlet V, valve for the separation between the electrochemical pre-chamher and the main UHV chamber SM, sample manipulator SP, sorption pump P, the turbomolecular pumps M, mass spectrometer S, sputter gun SC, sample of single crystals R, x-ray emission tube L, low-energy electron diffraction system H, heat lamp X, x-ray photoelectronic spectrometer and T, transfer rod with sample holder. 

SAM Characterization. TDS and XPS were performed in a UHV chamber with a base pressure of 10 10 mbar. The apparatus is equipped with a x-ray photoelectron spectrometer (Leybold Heraues, EA 10/100), a quadrupole mass spectrometer (Balzers QMA 400) with a mass range from 1 to 500, and an Ar+-sputter gun. For TDS the sample was mounted on a steel plate, which can be heated by tantalum wires spot welded on the backside of the plate [12], AFM was performed ex situ using a Nanosurf Easy scan 2 scanning probe microscope in tapping mode. 

Figure 2. Decomposition of Et NAuBr, in the x-ray beam of an x-ray photoelectron spectrometer. Peaks 1 and 2 refer to gold(lll) and peaks 3 and 4 refer to gold(I). Key to exposure time before spectra were recorded a, 15 min b, 3 h c, 24 h and d, control spectrum of Et NAuBrt. (Reproduced with permission from...

For investigating the adsorbed ion states, serial X-ray photoelectron spectrometer ES-100 was used. 

Figure 17.3.5 Schematic diagram of X-ray photoelectron spectrometer with an electrostatic hemispherical analyzer. The detector is usually a channel electron multipher. [From J. J. Pireaux and R. Sporken in M. Grasserbauer and H. W. Werner, Eds., Analysis of Microelectronic Materials and Devices, Wiley, New York, 1991, with permission.]...

Figure 24.27 Schematic diagram illustrating the basic design of an x-ray photoelectron spectrometer using a retarding lens system and a hemispherical electrostatic analyser. (From P. M. A. Sherwood in Spectroscopy, vol. 3. B. P. Straughan and S. Walker, eds. London Chapman and Hall, Ltd., 1976.)...

XPS (x-ray photoelectron spectrometer)— the method uses x-ray irradiation to cause core electrons to be ejected from elements near the surface of a sample. Analysis of the kinetic energies of these ejected electrons, also known as photoelectrons, yields information about the elemental composition and chemical state of the surface. 

The authors would like to thank Graham Beamson, RUSTI, Daresbury Laboratory, Warrington, UK for the permission to use data from the Scienta X-ray Photoelectron Spectrometer and to Jiri Homola, Institute of Radioengineering and Electronics, Academy of Sciences of the Czech Republic and University of Washington, Department of Electrical Engineering, Seattle, USA, and to V Hnatowicz, Nuclear Physics Institute, Academy of Sciences of the Czech Republic for cooperation on some parts of this chapter. 

---