ASTM_E_2108_-_10.pdf

Designation:E210810Standard Practice forCalibration of the Electron Binding-Energy Scale of anX-Ray Photoelectron Spectrometer1This standard is issued under the fixed designation E2108;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice describes a procedure for calibrating theelectron binding-energy(BE)scale of an X-ray photoelectronspectrometer that is to be used for performing spectroscopicanalysis of photoelectrons excited by unmonochromated alu-minum or magnesium K X-rays or by monochromatedaluminum K X-rays.1.2 The calibration of the BE scale is recommended afterthe instrument is installed or modified in any substantive way.Additional checks and,if necessary,recalibrations are recom-mended at intervals chosen to ensure that BE measurements arestatistically unlikely to be made with an uncertainty greaterthan a tolerance limit,specified by the analyst,based on theinstrumental stability and the analysts needs.Information isprovided by which the analyst can select an appropriatetolerance limit for the BE measurements and the frequency ofcalibration checks.1.3 This practice is based on the assumption that the BEscale of the spectrometer is sufficiently close to linear to allowfor calibration by measurements of reference photoelectronlines having BEs near the extremes of the working BE scale.Inmost commercial instruments,X-ray sources with aluminum ormagnesium anodes are employed and BEs are typically mea-sured over the 01000 eV range.This practice can be used forthe BE range from 0 eV to 1040 eV.1.4 The assumption that the BE scale is linear is checked bya measurement made with a reference photoelectron line orAuger-electron line that appears at an intermediate position.Asingle check is a necessary but not sufficient condition forestablishing linearity of the BE scale.Additional checks can bemade with specified reference lines on instruments equippedwith magnesium or unmonochromated aluminum X-raysources,with secondary BE standards,or by following theprocedures of the instrument manufacturer.Deviations fromBE-scalelinearitycanoccurbecauseofmechanicalmisalignments,excessive magnetic fields in the region of theanalyzer,or imperfections or malfunctions in the power sup-plies.This practice does not check for,nor identify,problemsof this type.1.5 After an initial check of the BE-scale linearity andmeasurements of the repeatability standard deviation for themain calibration lines for a particular instrument,a simplifiedprocedure is given for routine checks of the calibration atsubsequent times.1.6 This practice is recommended for use with X-rayphotoelectron spectrometers operated in the constant-pass-energy or fixed-analyzer-transmission mode and for which thepass energy is less than 200 eV;otherwise,depending on theconfiguration of the instrument,a relativistic equation could beneeded for the calibration.The practice should not be used forinstruments operated in the constant-retardation-ratio mode atretardation ratios less than 10,for instruments with an energyresolution above 1.5 eV,or in applications for which BEmeasurements are desired with tolerance limits of 60.03 eV orless.1.7 On instruments equipped with a monochromated alumi-num K X-ray source,a measurement of the position of aspecified Auger-electron line can be used,if desired,todetermine the average energy of the X-rays incident on thespecimen.This information is needed for the determination ofmodified Auger parameters.1.8 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.9 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This practice is under the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.03 on Auger ElectronSpectroscopy and X-Ray Photoelectron Spectroscopy.Current edition approved Nov.1,2010.Published December 2010.Originallyapproved in 2000.Last previous edition approved in 2005 as E2108 05.DOI:10.1520/E2108-10.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E456 Terminology Relating to Quality and StatisticsE673 Terminology Relating to Surface Analysis(Withdrawn2012)3E902 Practice for Checking the Operating Characteristics ofX-Ray Photoelectron Spectrometers(Withdrawn 2011)3E1016 Guide for Literature Describing Properties of Elec-trostatic Electron SpectrometersE1078 Guide for Specimen Preparation and Mounting inSurface Anal