• Title, Summary, Keyword: X-ray Photoelectron Spectroscopy

Search Result 1,348, Processing Time 0.041 seconds

Non-Destructive Evaluation for Material of Thermal Barrier Coatings (단열 코팅재료의 비파괴 평가기법)

  • Lee Chul-Ku;Kim Tae-Hyung
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.14 no.1
    • /
    • pp.44-51
    • /
    • 2005
  • Material degradation is a multibillion-dollar problem which affects all the industries amongst others. The last decades have seen the development of newer and more effective techniques such as Focused-ion beam(FIB), Transmission electron microscopy(TEM), Secondary-ion mass spectroscopy(SIMS), auger electron spectroscopy(AES), X-ray Photoelectron spectroscopy(XPS) , Electrochemical impedance spectroscopy(EIS), Photo- stimulated luminescence spectroscopy(PSLS), etc. to study various forms of material degradation. These techniques are now used routinely to obtain information on the chemical state, depth profiling, composition, stress state, etc. to understand the degradation behavior. This paper describes the use of these techniques specifically applied to materials degradation and failure analysis.

Surface Analysis of Modified Polymer Samples by X-Ray Photoelectron Spectroscopy and Rutherford Backscattering Spectroscopy (X-선 광전자 분광법 및 라더포드 후방산란법에 의한 개질된 고분자 시료의 표면분석)

  • Park, Sung-Woo;Kim, Dong-Hwan;Kim, Young-Man;Park, Byung-Sun;Han, Wan-Soo;Suh, Bae-Suk
    • Analytical Science and Technology
    • /
    • v.7 no.3
    • /
    • pp.301-313
    • /
    • 1994
  • X-Ray Photoelectron Spectroscopy(XPS) and Rutherford Backscattering Spectroscopy(RBS) are used for the analysis of additives, examination of chemical structure and determination of identity with qualitative and quantitative analysis of surface elements, binding energy level and depth profiling in the surface. We analyzed surface of polyethylene, acrylonitrile butadien rubber, polypropylene, glass, fiber and paper treated with $XeF_2$ or C-F plasma by XPS and RBS. It was found that fluoro element was penetrated to sample surface and the distribution of surface elements are different than untreated samples.

  • PDF

X-ray Photoelectron Spectroscopy Study of LaFeO3 Powders Synthesized by Solution Combustion (용액연소법으로 제조한 LaFeO3의 XPS 특성)

  • Hwang, Yeon;Kang, Dae-Sik;Park, Mi-Hye;Cho, Sung-Baek
    • Korean Journal of Materials Research
    • /
    • v.18 no.6
    • /
    • pp.313-317
    • /
    • 2008
  • [ $LaFeO_3$ ] powders were synthesized using a method involving solution combustion, and the surface properties of these powders were examined by x-ray photoelectron spectroscopy. As the amount of fuel increased during the synthesis, the $LaFeO_3$ powders became amorphous with a large plate-like shape. It was found that the O 1s spectra were composed of two types of photoelectrons by deconvolutioning the spectra. Photoelectrons with higher binding energy come from adsorbed oxygen ($O^-$) whereas those with lower energy come from lattice oxygen ($O^{2-}$). The ratio of adsorbed and lattice oxygen increased as the ratio of the fuel and nitrate (${\Phi}$) increased. The binding energy of both types of oxygen increased as ${\Phi}$ increased due to the formation of carbonates.

The Effects of Ar-ion Bombardment and Annealing of D2O/Zircaloy-4 Surfaces Using XPS and UPS

  • Oh, Kyung-Sun;Kang, Yong-Cheol
    • Bulletin of the Korean Chemical Society
    • /
    • v.28 no.8
    • /
    • pp.1341-1345
    • /
    • 2007
  • The surface chemistry of D2O dosed Zircaloy-4 (Zry-4) surface followed by Ar-ion bombardment and annealing was studied by means of X-ray photoelectron spectroscopy (XPS) and Ultraviolet photoelectron spectroscopy (UPS). In the XPS study, Ar-ion bombardment caused decrease of the oxygen on the surface region of Zry-4 and therefore led to change the oxidation states of the zirconium from oxide to metallic form. In addition, oxidation states of zirconium were changed to lower oxidation states of zirconium due to depopulation of oxygen on the surface region by annealing. Up to about 787 K, the bulk oxygen diffused out to the subsurface region and after this temperature, the oxygen on the surface of Zry-4 was depopulated. UPS study showed that the valence band spectrum of the D2O exposed Zry-4 exhibited a dominant peak at around 13 eV and no clear Fermi edge was detected. After stepwise Ar+ sputtering processes, the decrease of the oxygen on the surface of Zry-4 led to suppress the dominant peak around 13 eV, the peak around 9 eV and develop a new peak of the metallic Zr 4d state (20.5-21.0 eV) at the Fermi level.

Interfacial Natures and Controlling Morphology of Co Oxide Nanocrystal Structures by Adding Spectator Ni Ions

  • Gwag, Jin-Seog;Sohn, Young-Ku
    • Bulletin of the Korean Chemical Society
    • /
    • v.33 no.2
    • /
    • pp.505-510
    • /
    • 2012
  • Cobalt oxide nanostructure materials have been prepared by adding several concentrations of spectator Ni ions in solution, and analyzed by electron microscopy, X-day diffraction, calorimetry/thermogravimetric analysis, UV-vis absorption, Raman, and X-ray photoelectron spectroscopy. The electron microscopy results show that the morphology of the nanostructures is dramatically altered by changing the concentration of spectator ions. The bulk XRD patterns of $350^{\circ}C$-annealed samples indicate that the structure of the cobalt oxide is all of cubic Fd-3m $Co_3O_4$, and show that the major XRD peaks shift slightly with the concentration of Ni ions. In Raman spectroscopy, we can confirm the XRD data through a more obvious change in peak position, broadness, and intensity. For the un-sputtered samples in the XPS measurement process, the XPS peaks of Co 2p and O 1s for the samples prepared without Ni ions exhibit higher binding energies than those for the sample prepared with Ni ions. Upon $Ar^+$ ion sputtering, we found $Co_3O_4$ reduces to CoO, on the basis of XPS data. Our study could be further applied to controlling morphology and surface oxidation state.

Soft X-ray Nano-spectroscopy for Electronic Structures of Transition Metal Oxide Nano-structures

  • Oshima, Masaharu
    • Applied Science and Convergence Technology
    • /
    • v.23 no.6
    • /
    • pp.317-327
    • /
    • 2014
  • In order to develop nano-devices with much lower power consumption for beyond-CMOS applications, the fundamental understanding and precise control of the electronic properties of ultrathin transition metal oxide (TMO) films are strongly required. The metal-insulator transition (MIT) is not only an important issue in solid state physics, but also a useful phenomenon for device applications like switching or memory devices. For potential use in such application, the electronic structures of MIT, observed for TMO nano-structures, have been investigated using a synchrotron radiation angle-resolved photoelectron spectroscopy system combined with a laser molecular beam epitaxy chamber and a scanning photoelectron microscopy system with 70 nm spatial resolution. In this review article, electronic structures revealed by soft X-ray nano-spectroscopy are presented for i) polarity-dependent MIT and thickness-dependent MIT of TMO ultrathin films of $LaAlO_3/SrTiO_3$ and $SrVO_3/SrTiO_3$, respectively, and ii) electric field-induced MIT of TMO nano-structures showing resistance switching behaviors due to interfacial redox reactions and/or filamentary path formation. These electronic structures have been successfully correlated with the electrical properties of nano-structured films and nano-devices.

Biological Synthesis of Au Core-Ag Shell Bimetallic Nanoparticles Using Magnolia kobus Leaf Extract (목련잎 추출액을 이용한 Au Core-Ag Shell 합금 나노입자의 생물학적 합성)

  • Song, Jae Yong;Kim, Beom Soo
    • Korean Chemical Engineering Research
    • /
    • v.48 no.1
    • /
    • pp.98-102
    • /
    • 2010
  • Magnolia kobus leaf extract was used for the synthesis of bimetallic Au core-Ag shell nanoparticles. Gold seeds and silver shells were formed by first treating aqueous solution of $HAuCl_4$ and then $AgNO_3$ with the plant leaf extract as reducing agent. UV-visible spectroscopy was monitored as a function of reaction time to follow the formation of bimetallic nanoparticles. The synthesized bimetallic nanoparticles were characterized with transmission electron microscopy(TEM), energy dispersive X-ray spectroscopy(EDS), and X-ray photoelectron spectroscopy(XPS). TEM images showed that the bimetallic nanoparticles are a mixture of plate(triangles, pentagons, and hexagons) and spherical structures. The atomic Ag contents of the bimetallic Au/Ag nanoparticles determined from EDS and XPS analysis were 34 and 65 wt%, respectively, suggesting the formation of bimetallic Au core-Ag shell nanostructure. This core-shell type nanostructure is expected to have potential for application in surface enhanced Raman spectroscopy and in the sensitive detection of biomolecules.

Investigation of Liquid Crystal Alignment on ion beam exposed polystyrene surface (이온빔을 조사한 폴리스타일렌 기판에서의 액정의 배향특성)

  • Hwang, Hyun Suk;Lee, Jong-Deok;Rho, Jungkyu;Han, Jeong-Min
    • Journal of Satellite, Information and Communications
    • /
    • v.9 no.1
    • /
    • pp.33-37
    • /
    • 2014
  • This paper introduces homogeneous liquid crystal (LC) orientations on chemically modulated polystyrene (PS) surfaces using various ion beam (IB) exposure time. Transparent PS was replaced with conventional polyimide material. As a non-contact process, IB bombardment process induced LC orientation in the direction parallel to the IB process. Through x-ray photoelectron spectroscopy, it was shown that the chemical compositional changes of the IB-irradiated PS surfaces were determined as a function of IB exposure time.Using this analysis, the optimal IB bombardment condition was determined at IB exposure time of up to 15 s. Moreover, thermal stability on IB-irradiated PS surfaces were carried out which showed that a relatively high IB exposure time induced a thermally stable LC alignment property.

Structural Studies of Thin Film Boron Nitride by X-ray Photoelectron Spectroscopy

  • Kim, Jong-Seong
    • Journal of Sensor Science and Technology
    • /
    • v.5 no.1
    • /
    • pp.51-56
    • /
    • 1996
  • Structural properties of rf sputtered boron nitride films were studied as a function of deposition parameters such as nitrogen pressure, substrate temperature and substrate bias using X-ray photoelectron spectroscopy and Auger electron spectroscopy. Composition and information on chemical bonding of resultant films was determined by XPS. XPS core level spectra showed that ratio of boron to nitrogen varied from 3.11 to 1.45 with respect to partial nitrogen pressure. Curve fitting of XPS spectra revealed three kinds of bonding mechanism of boron in the films. XPS peak positions of both B 1s and N 1s shifted to higher energy with higher nitrogen pressure as well as increase in substrate bias voltage. AES was used to see possible contamination of films by carbon or oxygen as well.

  • PDF

Characterization of Surface Oxides in Gold Thin Films with V- and Ti- underlays by AES and XPS (AES/XPS를 이용한 Au/V, Au/Ti 박막의 표면산화물 분석)

  • Kim, Jin -Young
    • Journal of the Korean Vacuum Society
    • /
    • v.1 no.1
    • /
    • pp.100-105
    • /
    • 1992
  • Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) analyses have been performed on double-structured Au/V and Au/Ti thin films after heat treatment at 500$^{\circ}$C in air. V- and Tiunderlays sandwiched between gold thin films and SiOz substrates form oxides on the free surface of gold films during the heat treatment. The chemical compositions of the oxides were identified as V205 and TiOz in Au/V and Au/Ti thin films, respectively.

  • PDF