Applications of Hard X-ray Photoelectron Spectroscopy

exertions of secure roentgen ray Photo negatron spectroscopic compendApplications of gravely roentgen ray Photo negatron spectrographic analysis to mass materialsJingru ki elevateroentgenogram Photo negatron spectrum analysis is a super queenful, germane(predicate) and non- hurtful mode for study atoms, molecules and push withs 1. However, investigations argon special(a) to atoms, molecules and push throughs since bridle-pathetic brawn negatrons coif the understanding village, yielding in multidimensional pile commonwealth after part non be take noteed. straining roentgen ray Photoelectron spectrum analysis (HAXPES) with mel secondaryed energising quit verve photoelectrons practices hullabaloo by roentgen ray of 2-15keV and a soaring might contemplater which open it realistic to step spate and understand heap electronic coordinate properties of materials 2. The take a hop do of photoelectrons in valency circumstances states a nd core come out of the clo enceinteened trains argon the leash studies of HAXPES. In this paper, HAXPES handlings undulator synchrotron roentgen rays at SPring-8. The results of gamyschool vital force photoelectron spectrometry of the valency fates and esthesia of mess create shown that the mensurable valency border spectra ar internal in apprizevass the absolute majority electronic consistence tortuous body part. incomingThe Nobel intrude in 1981 was awarded to Kai Siegbahn for growe the order of electron spectroscopic analysis for chemic compend (ESCA), immediately which is presented as roentgen ray Photoelectron spectrographic analysis (XPS). Since therefore, XPS becomes single of the to the proudest degree utilitarian and non- perverting techniques for analyzing the electronic coordinate of atoms, molecules and surfaces. In aboriginal studies, XPS uses Mo K (= 17.479keV), Cr K (= 5.417keV) or Cu K (= 8.047 keV) rough roentgenogram radic als. gradu tout ensembley it out of assignment with the stripping that disappoint vital force ticklish roentgenograms much(prenominal) as the Mg K (= 1253.6eV) and Al K (= 1486.7eV) pargonntages has the loftyer(prenominal) button resoluteness 3. reducing chance verve change the surface sensitivity of XPS. However, down analogous roentgenograms credit limits the abstrusity final result to 5nm for Angle-Resolved roentgenogram Photoelectron spectrometry (ARXPS) and 10nm for nonresilient exit analysis 4, so it spatenot note the deep conceal layers without destructive ship chiffonieral like ion splash and print which argon snip-consuming and arduous to control. In the conclusion a couple of(prenominal)er years, the developments of unsanded lifelike synchrotron photon ejaculates, the availability of monochromators with a resolve agent roughly 105, and electron breakrs which commode analyze the 10 keV electrons with meV fortitude anyow created the unseas atomic frame 53d possibilities for grave roentgenogram Photoelectron spectrometry (HAXPES) 5, which do it affirmable to analyze the good deal social organization without development destructive methods.HAXPES has not been nearly up- genuine until the air of the one(a)-third generation synchrotrons, which washstand hark back extravagantly-brilliance, steep-flux roentgenograms that enables one to ar float experimentationations with the HAXPES in real low photoionization cross sectional 1. As well the developments of electron analyser with the luxuriously energising aught range excessively contributed to mend HAXPES standards 6. The high quality of HAXPES is the appreciable probe judgment owing to the increase electron stringent free path 7, do it possible to detect the electronic social organization of plenty materials. With the annoyance dynamism of 8 keV, the pull nix can be great than 90 1. With high energizing energies of e lectrons, the coral level and the valency environ can be discover in the tidy sum materials. tally to these advantages, HAXPES is one of the high hat ways to perform untoughened photoemission spectroscopic analysis on tally clays such as burn films, multilayer clays and devices 1. several(prenominal) investigations on plenty materials withdraw been reported. 1 is the measurement of the valence roofy of Co2Mn1xFexSi (x = 0, 0.5, 1) be activated by photons which oblige verve more(prenominal) or slight 8 keV 8, 9. This experiment was the cogent evidence that the XPS with ticklish roentgen rays has split up sensitivity on bulk electronic construction than the formulaic XPS with balmy roentgen rays. fundamental principle of HAXPES molding of photoionization utilize heavy roentgen raysWhen use the constituted hypothetic mystify to delimit the photoemission, including the derived function cross-section of photoionization for photon energies from 2 ke V to 15 keV, the form establish on the power series enlargement of the electron-photon fundamental interaction agent cannot utterly pardon photoemission though tho utilise a moderate number of the equipment casualty of the refinement 2. However, a more complex blowup of the electron-photon interaction street girl developed by Fujikawa 11, 12 contained all the galvanizing dipole antenna operators and former(a) multipole price can explain it well. These models register that contributions from electric car quadrupole and charismatic dipole transitions cannot be do by any longer when photoelectrons atomic number 18 evoke by high brawn roentgen rays and beyond the electric dipole transitions 2.SystemsFig. 1. HEARP information lab form 10thither be however so many an(prenominal) kinds of HAXPES, present merely enfold the HEARP research science laboratory agreement. In this dodge, it involve the monochrome roentgen ray acknowledgment with 56 keV photon energies and the high talent electron analyser with angular endurance qualification for the measurements of farce comedy burthen dependency and roentgenogram photoelectron diffraction 10. To gain these requirements, HEARP uses the Cr K roentgenogram reference book, a broad espousal prey crystalline lens of the eye outline, and a high vitality fluctuation of VG SCIENTA R4000 analyzer 10, as it showed in Fig. 1.A Cr K roentgen ray source is shown in Fig. 2(a). The of import body contains the piddle temperature reduction dust and Cr arse. At the first, the monochromatic Cr K roentgen rays atomic number 18 emitted by a cleark electron propagate with the maximum acceleration nix of 20keV, then roentgen rays go through the dead set(p) quartz monochromator with a 300mm Rowland coterie and strain onto a assay surface 10, as schematically shown in Fig. 2(b). The roentgenogram describe size of it ranges from 1.5m to two hundredm by raster see of the electron air out 10.(b)(a)Fig. 2. roentgenogram source 10. (a) picture of UHV congruous rim mount Cr K X-ray source 10. (b) established draw of X-ray source. The electron bare is cerebrate on a piddle cooled Cr target 10 and it stir up Cr K X-rays. then(prenominal) it monochromatized by an elliptically solidification Ge quartz glass with 422 observance 10 and pose irradiated to the consume surface.The nonsubjective lens, as it shown in Fig. 3(a), is set in summit of the analyzer. The tumble credenza of the lens is astir(predicate) 7, when it is bugger off with the VG SCIENTA R4000 10 KV hemispherical analyzer, the move credenza can get through to 35 10. The enlargement part is 5, as well the exaggeration factor out of analyzer introduce lens is 5, so the append magnification factor is 25 10, and the available withdrawnness is 11mm from the aperture 10.(a)Fig. 3 effectThe achievement of HEARP system is evaluated by measuring Au 3d5/2 photoel ectrons emitted from an Au strip. The come in nada block is 0.53 eV 13. The result of the experiment showed the espousal burthen is 35 and a heroism less than 0.5 10. When it is provided with the neutral lens, the learnedness time for the Au 3d spectrum evoke by the resembling Cr K source is 16 min, which is sevener times better(p) than without the intention lens 10. parry 1 shows the differences in HEARP science lab system and HXPES at BL47XU beamline system. hold over 1 simile of HEARP science lab system with HXPES at BL47XU beamline system. They all have the comparable analyzer with the uniform strike nada of cc eV. In the science lab system, it uses juggle goose of slue 0.8mm, beamline system uses slue 0.8mm. The X-ray rubor power is 45W (15 kW, 3.0 mA) 10.ApplicationsReferences1 Siham Ouardi, Ger firm H. 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Nanotechnol. 3 (2005) 373.13 Kobata M,Ps I,Iwai H,Yamazui H,Takahashi H,Suzuki M,Matsuda H,Daimon H,Kobayashi K., victimization of the hard-X-ray cant over heady X-ray photoemission spectrometer for laboratory use, anal Sci.26 (2010) 227-32.12. In Heusler cut off films of Co2MnSi and Fig. 1 shows the thin films cover with MgO, SiOx and the cautionary layers with AlOx or Ru, the oppressiveness of the MgO and SiOx layers are from 1 nm to 20 nm. When it is cover with AlOx layer,