18:09:13Basic XPS Information Section

The Basic XPS Information Section provides fundamental XPS spectra, BE values, FWHM values, BE tables, overlays of key spectra, histograms and a table of XPS parameters.
The Advanced XPS Information Section is a collection of additional spectra, overlays of spectra, peak-fit advice, data collection guidance, material info,
common contaminants, degradation during analysis, auto-oxidation, gas capture study, valence band spectra, Auger spectra, and more.
Published literature references, and website links are summarized at the end of the advanced section.
→  Periodic Table                      XPS Database of Polymers                 →Six (6) BE Tables

 

Beryllium (Be)

 

Beryl – Be3Al2Si6O18 Beryllium Metal – Beo Beryllonite – BePO4

 

  Page Index
  • Expert Knowledge Explanations

 

Beryllium (Beo) Metal

Peak-fits, BEs, FWHMs, and Peak Labels

Beryllium, (Beo) Metal
Be (1s) Spectrum – raw
 Beryllium, (Beo) Metal
Peak-fit of Be (1s) Spectrum

→  Periodic Table      

 Survey Spectrum of Beryllium (Beo)
with Peaks Integrated, Assigned and Labelled
→  Periodic Table 

 

XPS Signals for Pure Beryllium (Beo) Metal

Spin-Orbit Term,  BE (eV) Value, and Scofield σ for Aluminum Kα X-rays (1486 eV, 8.33 Ang)

Overlaps Spin-Orbit Term BE (eV) Value Scofield σ from 1486 eV X-rays IMFP (TPP-2M) in Å
Ni (3s), Ce (4d) & Rb (3d) overlap Be (1s) 111.80 0.1947 31.6

σ:  abbreviation for the term Scofield Photoionization Cross-Section which are used with IMFP and TF to generate RSFs and atom% quantitation

Intrinsic Plasmon Peak:  ~20 eV above peak max
Expected Bandgap for BeO: 10.5 eV 

*Scofield Cross-Section (σ) for C (1s) = 1.0

→  Periodic Table      

 

Valence Band Spectrum from Beo Metal

Fresh exposed bulk produced by extensive Ar+ ion etching

 

Plasmon Peaks from Beo Metal
Fresh exposed bulk produced by extensive Ar+ ion etching

Be (1s) – extended range Be (1s) – extended range – with vertical zoom

 

→  Periodic Table      

 

Be (KLL) Auger Peaks from Beo Metal
Fresh exposed bulk produced by extensive Ar+ ion etching

→  Periodic Table      

 

Artefacts Caused by Argon Ion Etching

C (1s) from Beryllium Carbide(s) that formed Argon Trapped in Beryllium

 

→  Periodic Table 

Side-by-Side Comparison of
Be Native Oxide & BeO
Peak-fits, BEs, FWHMs, and Peak Labels
Be Native Oxide Beryllium Oxide, BeO
Be (1s) from Native Oxide on Beo metal
Flood Gun OFF
As-measured, C (1s) at 286.3 eV		 Be (1s) from BeO pressed pellet
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 

C (1s) from Native Oxide on Beo metal
Flood Gun OFF
As-measured, C (1s) at 286.3 eV

 

C (1s) from BeO pressed pellet
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 

O (1s) from Native Oxide on Beo metal
Flood Gun OFF
As-measured, C (1s) at 286.3 eV

 

O (1s) from BeO pressed pellet
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

Copyright ©:  The XPS Library 

→  Periodic Table      

 

Overlays of Spectra
from Beo metal, Native Beryllium Oxide and BeO

Caution: BEs from Grounded Native Oxides can be Misleading when Flood Gun is ON

Be (1s) Overlay of Pure Beo Metal and Be Native Oxide
Native Oxide C (1s) = 286.3 eV  (FG Off)
Chemical Shift: 2.9
  Be (1s) Overlay of Pure Beo Metal and Pure BeO
Pure Oxide C (1s) = 285.0 eV
Chemical Shift: 1.7


Overlay of Be (1s)
Pure Beo Metal, Be Native Oxide & Pure BeO

Features  Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Valence Band Spectra
Beo, BeO

Beo BeO


Overlay of Valence Band Spectra
from Beo and BeO

→  Periodic Table      

 

Survey Spectrum of Beryllium Oxide (BeO)
with Peaks Integrated, Assigned and Labelled

 

 

Survey Spectrum of Beryllium (Be) Native Oxide
with Peaks Integrated, Assigned and Labelled

→  Periodic Table      

 

Beryllium Minerals, Gemstones, and Chemical Compounds

 
BeO (Extreme Poison) Red Beryl – Be3Al2Si6O18 Blue Beryl – Be3Al2Si6O18 Heliodor – Be3Al2Si6O18

 


Six (6) Chemical State Tables of Be (1s) BEs

 

  • The XPS Library Spectra-Base
  • PHI Handbook
  • Thermo-Scientific Website
  • XPSfitting Website
  • Techdb Website
  • NIST Website

 

 

Notes of Caution when using Published BEs and BE Tables from Insulators and Conductors:

  • Accuracy of Published BEs
    • The accuracy depends on the calibration BEs used to calibrate the energy scale of the instrument.  Cu (2p3/2) BE can vary from 932.2 to 932.8 eV for old publications
    • Different authors use different BEs for the C (1s) BE of the hydrocarbons found in adventitious carbon that appears on all materials and samples.  From 284.2 to 285.3 eV
    • The accuracy depends on when the authors last checked or adjusted their energy scale to produce the expected calibration BEs
  • Worldwide Differences in Energy Scale Calibrations
    • For various reasons authors still use older energy scale calibrations
    • Some authors still adjust their energy scale so Cu (2p3/2) appears at 932.2 eV or 932.8 eV because this is what the maker taught them
    • This range causes BEs in the higher BE end to be larger than expected
    • This variation increases significantly above 600 eV BE
  • Charge Compensation
    • Samples that behave as true insulators normally require the use of a charge neutralizer (electron flood gun with or without Ar+ ions) so that the measured chemical state spectra can be produced without peak-shape distortions or sloping tails on the low BE side of the peak envelop.
    • Floating all samples (conductive, semi-conductive, and non-conductive) and always using the electron flood gun is considered to produce more reliable BEs and is recommended.
  • Charge Referencing Methods for Insulators
    • Charge referencing is a common method, but it can produce results that are less reliable.
    • When an electron flood gun is used, the BE scale will usually shift to lower BE values by 0.01 to 5.0 eV depending on your voltage setting. Normally, to correct for this flood gun induced shift, the BE of the hydrocarbon C (1s) peak maximum from adventitious carbon is used to correct for the charge induced shift.
    • The hydrocarbon peak is normally the largest peak at the lowest BE.
    • Depending on your preference or training, the C (1s) BE assigned to this hydrocarbon peak varies from 284.8 to 285.0 eV.  Other BEs can be as low as 284.2 eV or as high as 285.3 eV
    • Native oxides that still show the pure metal can suffer differential charging that causes the C (1s) and the O (1s) and the Metal Oxide BE to be larger
    • When using the electron flood gun, the instrument operator should adjust the voltage and the XY position of the electron flood gun to produce peaks from a strong XPS signal (eg O (1s) or C (1s) having the most narrow FWHM and the lowest experimentally measured BE.

→  Periodic Table 

 

Table #1

Be (1s) Chemical State BEs from:  “The XPS Library Spectra-Base”

C (1s) BE = 285.0 eV for TXL BEs
and C (1s) BE = 284.8 eV for NIST BEs

Element Atomic # Compound As-Measured by TXL or NIST Average BE Largest NIST BE Hydrocarbon
C (1s) BE 		 Source
Be 4 Be – element 111.8 eV     The XPS Library
Be 4 Be-O (N*4) 113.7 eV 114 eV 284.8 Avg BE – NIST
Be 4 Be-O 113.5 eV   285.0 The XPS Library
Be 4 Native BeOx 114.8 eV   286.3 The XPS Library
Be 4 Be-F2 (N*2) 115.3 eV 116.1 eV 284.8 Avg BE NIST
Be 4 Be-F2 116.4 eV   285.0 The XPS Library
Be 4 Be-(OH)2       The XPS Library
Be 4 Be-CO3       The XPS Library
Be 4 Be-SO4       The XPS Library
Be 4 Be-l2       The XPS Library

Charge Referencing:

  • (N*number) identifies the number of NIST BEs that were averaged to produce the BE in the middle column.
  • Binding Energy Scale Calibration expects Cu (2p3/2) BE = 932.62 eV and Au (4f7/2) BE = 83.98 eV.  BE (eV) Uncertainty Range:  +/- 0.2 eV
  • Charge Referencing of insulators is defined such that the Adventitious Hydrocarbon C (1s) BE (eV) = 285.0 eV.  NIST uses C (1s) BE = 284.8 eV 
  • Note:   Ion etching removes adventitious carbon, implants Ar (+), changes conductivity of surface, and degrades chemistry of various chemical states.
  • Note:  Ion Etching changes BE of C (1s) hydrocarbon peak.
  • TXL – abbreviation for: “The XPS Library” (https://xpslibrary.com).  NIST:  National Institute for Science and Technology (in USA)

→  Periodic Table 

Table #2

Be (1s) Chemical State BEs from:  “PHI Handbook”

C (1s) BE = 284.8 eV

→  Periodic Table 

Copyright ©:  Ulvac-PHI

Table #3

Be (1s) Chemical State BEs from:  “Thermo-Scientific Website”

C (1s) BE = 284.8 eV

Chemical state Binding energy, Be (1s)
CuxBey  as-received 113.3 eV
CuxBey  Ar+ cleaned 112.5 eV

→  Periodic Table 

Copyright ©:  Thermo Scientific 

Table #4

Be (1s) Chemical State BEs from:  “XPSfitting Website”

Chemical State BE Table derived by Averaging BEs in the NIST XPS database of BEs
C (1s) BE = 284.8 eV

→  Periodic Table 

Copyright ©:  Mark Beisinger

Table #5

Be (1s) Chemical State BEs from:  “Techdb.podzone.net” Website

XPS Spectra – Chemical Shift | Binding Energy
C (1s) BE = 284.6 eV

XPS(X線光電子分光法)スペクトル 化学状態 化学シフト ケミカルシフト

Element Level Compound B.E.(eV) min   max
Be 1s Be 111.8 ±0.3 111.5 ～ 112.0
Be 1s BeMoO4 113.8 ±0.3 113.5 ～ 114.1
Be 1s BeO 113.9 ±0.3 113.6 ～ 114.1
Be 1s BeRh2O4 113.9 ±0.3 113.6 ～ 114.1
Be 1s Na2BeF4 114.8 ±0.3 114.5 ～ 115.0
Be 1s BeF2 115.7 ±0.4 115.3 ～ 116.1
Be 1s NaBeF3 115.7 ±0.3 115.4 ～ 116.0

 

 


Histograms of NIST BEs from Be (1s)

Important Note:  NIST Database defines Adventitious Hydrocarbon C (1s) BE = 284.8 eV for all insulators.

Histogram indicates:  111.6 eV for Be0 based on 3 literature BEs Histogram indicates:  113.8 eV for BeO based on 4 literature BEs

Table #6

 
NIST Database of Be (1s) Binding Energies

NIST Standard Reference Database 20, Version 4.1

Data compiled and evaluated
by
Alexander V. Naumkin, Anna Kraut-Vass, Stephen W. Gaarenstroom, and Cedric J. Powell
©2012 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

Important Note:  NIST Database defines Adventitious Hydrocarbon C (1s) BE = 284.8 eV for all insulators.

 

Element Spectral Line Formula Energy (eV) Reference
Be 1s Be 111.30  Click
Be 1s Be 111.60  Click
Be 1s Be 111.80  Click
Be 1s Be 111.82  Click
Be 1s BeO 113.70  Click
Be 1s BeO 113.70  Click
Be 1s BeO 113.70  Click
Be 1s BeMoO4 113.70  Click
Be 1s BeRh2O4 113.80  Click
Be 1s BeO 114.00  Click
Be 1s Na2BeF4 114.70  Click
Be 1s BeF2 115.30  Click
Be 1s NaBeF3 115.30  Click
Be 1s BeF2 116.10  Click

→  Periodic Table 

 

 

Statistical Analysis of Binding Energies in NIST XPS Database of BEs

 

 

→  Periodic Table 

 

Advanced XPS Information Section

Spectra, BEs, Features, Guidance and Cautions
for XPS Research Studies on Beryllium Materials

 

 

XPS Spectra

from Common Beryllium Compounds

                             

Be (1s) = 111.8 eV:  Beo
Cu (2p3/2) BE = 932.65 eV		 Be (1s)  113.5 eV:  BeO
C (1s) BE = 285.0		 Be (1s) = 116.4 eV:  BeF2
C (1s) BE = 285.0 eV

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Overlay of Be (1s) Spectra shown Above

C (1s) BE = 285.0 eV

→  Periodic Table 

 

Plasmon Peaks from Beryllium Metal, Beo
 Fresh exposed bulk produced by extensive Ar+ ion etching

Be (1s) – Plasmon Peaks – Extended Range Spectrum Be (1s) – Plasmon Peaks -Extended Range Spectrum – Vertically Zoomed

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Native Oxide on Beryllium, Beo Metal
Naturally Formed at 25 Co 1 atm

Survey Spectrum from FRESH Native Oxide on Beo metal Be (1s) Chemical State Spectrum from FRESH Native Oxide on Beo
   
O (1s) Chemical State Spectrum from FRESH Native Oxide on Beo C (1s) Chemical State Spectrum from FRESH Native Oxide on Beo

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

 

Flood Gun Effect on Native Oxide of Beryllium

 

Native Oxide of Beryllium Disk – Sample GROUNDED
versus
Native Oxide of Beryllium Disk – Sample FLOATING

 

 

Native Oxide of Beryllium Disk – Sample Grounded

Electron Flood Gun:  0 Voltage (FG OFF), Min Voltage versus Max Voltage
Be (1s) O (1s) C (1s)
Differential Shift of BeO Peak is due to
Differential Charging		 Differential Shift of O (1s) Peak is due to
Differential Charging		 Differential Shift of Adventitious Carbon
is a Slightly Larger

 

Native Oxide of Beryllium Disk – Sample Floating

Electron Flood Gun:  0 Voltage (FG OFF), Min Voltage versus Max Voltage
Be (1s) O (1s) C (1s)
All Peaks Shift Linearly
NO Differential Charging		 All Peaks Shift Linearly
NO Differential Charging		 All Peaks Shift Linearly
NO Differential Charging
     
     

→  Periodic Table 

 

 

XPS Spectra
from Common Beryllium Compounds

Beryllium Oxide (BeO)
pressed pellet

Survey Spectrum from BeO Be (1s) Chemical State Spectrum from BeO

O (1s) Chemical State Spectrum from BeO
C (1s) Chemical State Spectrum from BeO

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Valence Band Spectra
Beo, BeO

Beo metal
Ion etched clean		 BeO powder
Charge Referenced so C (1s) = 285.0 eV

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

XPS Study of UHV Gas Capture by Freshly Ion Etched Beryllium
 
Reveals Chemical Shifts and Chemical States that Develop from Highly Reactive Pure Beo Metal

Surface was strongly Ar+ ion etched to remove all contaminants, and
then allowed to react overnight with the UHV Gases – CO, H2, H2O, O2 & CH4
that normally reside inside on the walls of the chamber, on the sample stage,
and on the nearby un-etched surface a total of 10-14 hours.  UHV pump was a Cryopump.
 
 
Be (1s) Signal
  O (1s) Signal C (1s) Signal
     
 
Copyright ©:  The XPS Library

 

Chemical State Depth Profile on Thin Beryllium Oxide
from JEOL 7830F Auger


Thin oxide produced by dipping clean Be metal into HNO3 for 60 sec

Be KLL Signal:   BeO at front -> Be metal at rear (normal display) O KLL Signal:   BeO at rear -> Be metal at front (display reversed)
   
   
   

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Chemical State Spectra from
Chemical Compounds or Alloys
that include Beryllium

 

 

Beryllium Alloys

   
XxCu XxCu
→  Periodic Table   
XxCu XxCu

 

Copyright ©:  The XPS Library 

 

XPS Facts, Guidance & Information

→  Periodic Table 

    Element   Beryllium (Be)
  
    Primary XPS peak used for Peak-fitting :   Be (1s)  
    Spin-Orbit (S-O) splitting for Primary Peak:   NO Spin-Orbit splitting for “s” orbitals
  
    Binding Energy (BE) of Primary XPS  Signal:   111.8 eV
  
    Scofield Cross-Section (σ) Value:   Be (1s) = 0.1947
  
    Conductivity:   Metal form is conductive
Resistivity = 36 nΩ⋅m (at 20 °C)
Native Oxide suffers Differential Charging		  
    Range of Be (1s) Chemical State BEs:   111.8 – 115.0 eV range   (Beo to BeF2)  
    Signals from other elements that overlap
Be (1s) Primary Peak:		   ??  
    Bulk Plasmons:   ~20 eV above peak max for pure metal  
    Shake-up Peaks:   ??  
    Multiplet Splitting Peaks:   not possible  

 

 

 General Information about
XXX Compounds:		   xx  
    Cautions – Chemical Poison Warning  

Be metal gas and BeO powder are toxic if breathed extensively.  Be extremely careful using BeO powder.

  

Copyright ©:  The XPS Library 

 

Information Useful for Peak-fitting Be (1s)

  • FWHM (eV) of Be (1s) from Pure Be metal:  ~0.69 eV using 50 eV Pass Energy after ion etching:
  • FWHM (eV) of Be (1s) from BeO:  ~1.73 eV using 50 eV Pass Energy  (before ion etching)
  • Binding Energy (BE) of Primary Signal used for Measuring Chemical State Spectra:  111.8 eV for Be (1s) with +/- 0.1 uncertainty
  • List of XPS Peaks that can Overlap Peak-fit results for Xx (1s): xx

→  Periodic Table 

 

General Guidelines for Peak-fitting XPS Signals

  • Typical Energy Resolution for Pass Energy (PE) setting used to measure Chemical State Spectra on Various XPS Instruments
    • Ag (3d5/2) FWHM (eV) = ~0.95 eV for PE 50 on Thermo K-Alpha
    • Ag (3d5/2) FWHM (eV) = ~1.00 eV for PE 80 on Kratos Nova
    • Ag (3d5/2) FWHM (eV) = ~0.95 eV for PE 45 on PHI VersaProbe
  • FWHM (eV) of Pure Elements: Ranges from 0.4 to 1.0 eV across the periodic table
  • FWHM of Chemical State Peaks in any Chemical Compound:  Ranges from 1.1 to 1.6 eV  (in rare cases FWHM can be 1.8 to 2.0 eV)
  • FWHM of Pure Element versus FWHM of Metal Oxide:  Pure element FWHM << Metal Oxide FWHM  (e.g. 0.8 vs 1.5 eV, roughly 2x)
  • If FWHM Greater than 1.6 eV:  When a peak FWHM is larger than 1.6 eV, it is best to add another peak to the peak-fit envelop.
  • BE (eV) Difference in Chemical States: The difference in chemical state BEs is typically 1.0-1.3 eV apart.  In rare cases, <0.8 eV.
  • Number of Peaks to Use:  Use minimum. Do not use peaks with FWHM < 1.0 eV unless it is a metal or a conductive compound.
  • Typical Peak-Shape:  80% G: 20% L,   or Voigt : 1.4 eV Gaussian and 0.5 eV Lorentzian
  • Spin-Orbit Splitting of Two Peaks (due to Coupling):  The ratio of the two (2) peak areas must be constrained.
  • Constraints on Peak-fitting: ??

Notes:

  • Other Oxidation States can appear as small peaks when peak-fitting
  • Pure element signals normally have asymmetric tails that should be included in the peak-fit.
  • Gaseous state materials often display asymmetric tails due to vibrational broadening.
  • Peak-fits of C (1s) in polymers include an asymmetric tail when the energy resolution is very high.
  • Binding energy shifts of some compounds are negative due to unusual electron polarization.

→  Periodic Table 

 

Quantitation Details and Information

Quantitation by XPS is often incorrectly done, in many laboratories, by integrating only the main peak, ignoring the Electron Loss peak, and the satellites that appear as much as 30 eV above the main peak.  By ignoring the electron loss peak and the satellites, the accuracy of the atom% quantitation is in error.

When using theoretically calculated Scofield cross-section values, the data must be corrected for the transmission function effect, use the calculated TPP-2M IMFP values, the pass energy effect on the transmission function, and the peak area used for calculation must include the electron loss peak area, shake-up peak area, multiplet-splitting peak area, and satellites that occur within 30 eV of the main peak.

→  Periodic Table 

 

Contaminants Specific to Beryllium Metal

  • Beryllium metal develops a thick native oxide due to the reactive nature of clean Beryllium metal.
  • The native oxide of BeOx is 6-7 nm thick.
  • Beryllium metal thin films often have a low level of iron (Fe) in the bulk as a contaminant or to strengthen the thin film
  • Beryllium forms a low level of carbide when the surface is ion etched inside the analysis chamber

 

 

Commonplace Contaminants

  • Carbon and Oxygen are common contaminants that appear on nearly all surfaces. The amount of Carbon usually depends on handling.
  • Carbon is usually the major contaminant.  The amount of carbon ranges from 5-50 atom%.
  • Carbon contamination is attributed to air-borne organic gases that become trapped by the surface, oils transferred to the surface from packaging containers, static electricity, or handling of the product in the production environment.
  • Carbon contamination is normally a mixture of different chemical states of carbon (hydrocarbon, alcohol or ether, and ester or acid).
  • Hydrocarbon is the dominant form of carbon contamination. It is normally 2-4x larger than the other chemical states of carbon.
  • Carbonate peaks, if they appear, normally appear ~4.5 eV above the hydrocarbon C (1s) peak max BE.
  • Low levels of carbonate is common on many metals that readily oxidize in the air.
  • High levels of carbonate appear on reactive metal oxides and various hydroxides.  This is due to reaction between the oxide and CO2 in the air.
  • Hydroxide contamination peak is due to the reaction with residual water in the lab air or the vacuum.
  • The O (1s) BE of the hydroxide (water) contamination normally appears 0.5 to 1.0 eV above the oxide peak
  • Sodium (Na), Potassium (K), Sulfur (S) and Chlorine (Cl) are common trace to low level contaminants
  • To find low level contaminants it is very useful to vertically expand the 0-600 eV region of the survey spectrum by 5-10X
  • A tiny peak that has 3 or more adjacent data-points above the average noise of the background is considerate to be a real peak
  • Carbides can appear after ion etching various reactive metals.  Carbides form due to the residual CO and CH4 in the vacuum.
  • Ion etching can produce low oxidation states of the material being analyzed.  These are newly formed contaminants.
  • Ion etching polymers by using standard Ar+ ion guns will destroy the polymer, converting it into a graphitic type of carbon

→  Periodic Table 

 

Data Collection Guidance

  • Chemical state differentiation can be difficult
  • Collect principal Be (1s) peak.
  • Long time exposures (high dose) to X-rays can degrade various polymers, catalysts, high oxidation state compounds
  • During XPS analysis, water or solvents can be lost due to high vacuum or irradiation with X-rays or Electron flood gun
  • Auger signals can sometimes be used to discern chemical state shifts when XPS shifts are very small

→  Periodic Table 

 

Data Collection Settings for Beryllium (Be)

  • Conductivity:  Beryllium readily develops a native oxide that is sensitive to Flood Gun – Differential Charging Possible – float sample recommended
  • Primary Peak (XPS Signal) used to measure Chemical State Spectra:  Be (1s) at 111.8 eV
  • Recommended Pass Energy for Measuring Chemical State Spectrum:  40-50 eV    (Produces Ag (3d5/2) FWHM ~0.7 eV)
  • Recommended # of Scans for Measuring Chemical State Spectrum:  4-5 scans normally   (Use 10-25 scans to improve S/N)
  • Dwell Time:  50 msec/point
  • Step Size:  0.1 eV/point   (0.1 eV/step or 0.1 eV/channel)
  • Standard BE Range for Measuring Chemical State Spectrum:  105 – 125 eV
  • Recommended Extended BE Range for Measuring Chemical State Spectrum:  100 – 150 eV
  • Recommended BE Range for Survey Spectrum:  -10 to 1,100 eV   (above 1,100 eV there are no useful XPS signals, except for Ge and Ga)
  • Typical Time for Survey Spectrum:  3-5 minutes for newer instruments, 5-10 minutes for older instruments
  • Typical Time for a single Chemical State Spectrum with high S/N:  5-10 minutes for newer instruments, 10-15 minutes for older instruments 

→  Periodic Table 

 

Effects of Argon Ion Etching

  • Carbides can appear after ion etching various reactive metals.  Carbides form due to the residual CO and CH4 in the vacuum.
  • Ion etching can produce low oxidation states of the material being analyzed.  These are newly formed contaminants.
  • Ion etching polymers by using standard Ar+ ion guns will destroy the polymer, converting it into a graphitic type of carbon

 

→  Periodic Table 

Copyright ©:  The XPS Library 
 
 
 
Gas Phase XPS or UPS Spectra
 
 
     
     
     
     
     
     
     
     
     
 
 
 
 
 
 

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