Basic 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

 

Lithium (Li)

 

Lithium Fluoride (single crystal) – LiF Lithium Metal – Lio  (in oil) Lithium Carbonate – Li2CO3

 

  Page Index
  • Expert Knowledge  Explanations


Lithium (Li+)

Peak-fits, BEs, FWHMs, and Peak Labels

 

  .
Lithium Fluoride (LiF)
Li (1s) Spectrum – raw
LiF single crystal – freshly exposed bulk
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
 Lithium Fluoride (LiF)
 Li (1s) Spectrum – Peak-fit
LiF single crystal – freshly exposed bulk
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

→  Periodic Table

 


Survey Spectrum of Lithium Fluoride, LiF
with Peaks Integrated, Assigned and Labelled

→  Periodic Table 

 

XPS Signals for Lithium

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
Fe (3p) & Mg (2p) overlaps Li (1s) 55.9 0.0568 45.8

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

Energy Loss:  ~15 eV above peak max
Expected Bandgap for LiF:  13-14 eV 

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

 

Side-by-Side Comparison of
LiI (pellet) & LiF (crystal)
Peak-fits, BEs, FWHMs, and Peak Labels

 
Lithium Iodide (LiI) Lithium Fluoride (LiF)
Li (1s) from LiI – crushed pellet
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV		 Li (1s) from LiF – single crystal
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

.
Lithium Iodide (LiI)
C (1s) from LiI – crushed pellet
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

Lithium Fluoride (LiF) 
C (1s) from LiF – single crystal
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

.
Lithium Iodide (LiI)
I (3d5/2) from LiI – crushed pellet
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

Lithium Fluoride (LiF) 
F (1s) from LiF – single crystal
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

Copyright ©:  The XPS Library 

 

Overlays of Li (1s) Spectra of
LiF with LiI and LiCl 

 Overlay of LiF and LiI – Li (1s)
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
  Overlay of LiF and LiCl – Li (1s)
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
→  Periodic Table  Copyright ©:  The XPS Library 

 

Overlay of
LiF, LiCl, and LiI – Li (1s) BE

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Comparison of
Carbonate and Sulfate Chemical States 

Li2CO3 and Li2SO4

Lithium Carbonate (Li2CO3) Lithium Sulfate (Li2SO4)
Li (1s) from Li2CO3 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV		 Li (1s) from Li2SO4 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
.

C (1s) from Li2CO3 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
C (1s) from Li2SO4 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV

→  Periodic Table 

O (1s) from Li2CO3 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV


O (1s) from Li2SO4 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
 
S (2p) from Li2SO4 – powder
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
 

 

→  Periodic Table 

Overlays of

Li (1s) and C (1s) Spectra
from Li2CO3 and Li2SO4

 Overlay of Li2CO3 and Li2SO4 – Li (1s) BE
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
  Overlay of Li2CO3 and Li2SO4 – C (1s) BE
Flood Gun ON,  BEs Charge Referenced to C (1s) BE at 285.0 eV
  Copyright ©:  The XPS Library 

 

Overlay of:
Li2CO3, LiCl, and LiF – Li (1s) BE

 

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Lithium Minerals, Gemstones, and Chemical Compounds

 
Muscovite – KAl2(AlSi3O10)(F,OH)2 Petalite – LiAlSi4O10 Triphylite – LiFePO4  Lepidolite – K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2

 

 

 

Six (6) Chemical State Tables of Li (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

Li (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 BE in NIST Hydrocarbon C (1s) BE Source
Li 3 Li – element ~54.7 eV   284.8 eV PHI Handbook
Li 3 Li-OH   (N*1) 54.9 eV   284.8 eV Avg BE – NIST
Li 3 Li2CO3 (N*2) 55.1 eV 55.2 eV 284.8 eV Avg BE – NIST
Li 3 Li2WO4 55.1 eV   285.0 eV The XPS Library
Li 3 Li2CO3 55.2 eV   285.0 eV The XPS Library
Li 3 Li2O 55.4 eV   285.0 eV The XPS Library
Li 3 Li2O (N*1) 55.6 eV 55.8 eV 284.8 eV Avg BE – NIST
Li 3 Li-F (N*3) 55.7 eV 56.7 eV 284.8 eV Avg BE – NIST
Li 3 Li-Cl (N*3) 55.8 eV 56.2 eV 284.8 eV Avg BE – NIST
Li 3 Li2SO4 55.8 eV   285.0 eV The XPS Library
Li 3 Li-F 55.9 eV   285.0 eV The XPS Library
Li 3 Li1B3O5 56.3 eV   285.0 eV The XPS Library
Li 3 Li-Cl 56.6 eV   285.0 eV The XPS Library
Li 3 Li-Br 56.6 eV   285.0 eV The XPS Library
Li 3 Li-I 56.8 eV   285.0 eV The XPS Library
Li 3 LiAlSi2O6 56.8 eV   285.0 eV 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

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

C (1s) BE = 284.8 eV

→  Periodic Table 

Copyright ©:  Ulvac-PHI

Table #3

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

C (1s) BE = 284.8 eV

Chemical state Binding energy (eV)
Li (1s)
Li2TiO3 54.7 eV
Li2CO3 55.4 eV
Li2B4O7 55.9 eV
LiF 56.1 eV
LiCl 56.3 eV

→  Periodic Table 

Copyright ©:  Thermo Scientific 

Table #4

Li (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

Li (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
Li 1s Li 54.8 ±0.3 54.5 ～ 55.0
Li 1s LiNbO3 55.0 ±0.3 54.7 ～ 55.2
Li 1s LiOH 55.0 ±0.2 54.8 ～ 55.2
Li 1s Li2CO3 55.2 ±0.3 54.9 ～ 55.4
Li 1s Li2O 55.5 ±0.2 55.3 ～ 55.7
Li 1s Li3PO4 55.5 ±0.2 55.3 ～ 55.7
Li 1s LiF 55.6 ±0.2 55.4 ～ 55.8
Li 1s Li4P2O7 55.6 ±0.2 55.4 ～ 55.8
Li 1s LiCl 56.0 ±0.3 55.7 ～ 56.3
Li 1s LiBr 56.8 ±0.3 56.5 ～ 57.0

→  Periodic Table 

 

 

 

Histograms of NIST BEs from Li (1s)

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

 

Histogram indicates:  55.0 eV for Lio based on 5 literature BEs Histogram indicates:  54.5 eV for LiF based on 4 literature BEs

Histogram indicates:  56.0 eV for LiCl based on 3 literature BEs 

Table #6

NIST Database of Li (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
Li 1s LiF 49.90  Click
Li 1s Li0.3Ni0.7O 53.60  Click
Li 1s LiNiO2 53.60  Click
Li 1s (Bi2O3)0.200(LiBO2)0.800 54.40  Click
Li 1s (Li2O)0.5(B2O3)0.494(Bi2O3)0.006 54.50  Click
Li 1s Li 54.60  Click
Li 1s Li/Si 54.70  Click
Li 1s Li/Si 54.70  Click
Li 1s (Li2O)0.5(B2O3)0.496(Bi2O3)0.004 54.70  Click
Li 1s Li 54.80  Click
Li 1s LiNbO3 54.80  Click
Li 1s LiBO2 54.80  Click
Li 1s LiBO2 54.80  Click
Li 1s (Li2O)0.4(B2O3)0.54(Bi2O3)0.06 54.80  Click
Li 1s (Li2O)0.5(B2O3)0.5 54.80  Click
Li 1s LiOH 54.90  Click
Li 1s Li 54.90  Click
Li 1s (Bi2O3)0.150(LiBO2)0.850 54.90  Click
Li 1s Li/Si 54.98  Click
Li 1s Li/Si 54.98  Click
Li 1s Li2WO4 55.00  Click
Li 1s Li2WO4 55.00  Click
Li 1s (Li2O)40(P2O5)24(MoO3)36 55.00  Click
Li 1s (Li2O)40(P2O5)18(MoO3)42 55.00  Click
Li 1s (Bi2O3)0.100(LiBO2)0.900 55.00  Click
Li 1s (Bi2O3)0.050(LiBO2)0.950 55.00  Click
Li 1s (Bi2O3)0.020(LiBO2)0.980 55.00  Click
Li 1s (Bi2O3)0.015(LiBO2)0.985 55.00  Click
Li 1s Li/Si 55.01  Click
Li 1s Li/Si 55.01  Click
Li 1s (Li2O)0.50(B2O3)0.50 55.05  Click
Li 1s Li 55.10  Click
Li 1s Li2WO4 55.10  Click
Li 1s (Li2O)40(P2O5)36(MoO3)24 55.10  Click
Li 1s (Li2O)50(P2O5)30(MoO3)20 55.10  Click
Li 1s (Bi2O3)0.010(LiBO2)0.990 55.10  Click
Li 1s (Bi2O3)0.250(LiBO2)0.750 55.10  Click
Li 1s (Bi2O3)0.002(LiBO2)0.998 55.10  Click
Li 1s (Li2O)0.4(B2O3)0.40(Bi2O3)0.20 55.10  Click
Li 1s (Li2O)0.4(B2O3)0.592(Bi2O3)0.008 55.10  Click
Li 1s (Li2O)0.5(B2O3)0.40(Bi2O3)0.10 55.10  Click
Li 1s Li2CO3 55.12  Click
Li 1s Li2CO3 55.20  Click
Li 1s LiN3 55.20  Click
Li 1s (Li2O)50(P2O5)25(MoO3)25 55.20  Click
Li 1s (Li2O)0.50(P2O5)0.35(WO3)0.15 55.20  Click
Li 1s (Li2O)0.50(P2O5)0.45(WO3)0.05 55.20  Click
Li 1s LiPO3 55.20  Click
Li 1s LiBO2 55.20  Click
Li 1s LiBO2 55.20  Click
Li 1s Li/Si 55.20  Click
Li 1s Li/Si 55.20  Click
Li 1s (Bi2O3)0.025(LiBO2)0.975 55.20  Click
Li 1s (Bi2O3)0.001(LiBO2)0.999 55.20  Click
Li 1s (Bi2O3)0.004(LiBO2)0.996 55.20  Click
Li 1s (Li2O)0.4(B2O3)0.50(Bi2O3)0.10 55.20  Click
Li 1s (Li2O)0.5(B2O3)0.499(Bi2O3)0.001 55.20  Click
Li 1s (Li2O)0.5(B2O3)0.42(Bi2O3)0.08 55.20  Click
Li 1s (Li2O)0.40(B2O3)0.60 55.25  Click
Li 1s (Li2O)40(P2O5)54(MoO3)6 55.30  Click
Li 1s (Li2O)50(P2O5)35(MoO3)15 55.30  Click
Li 1s (Li2O)60(P2O5)36(MoO3)4 55.30  Click
Li 1s (Li2O)0.50(P2O5)0.10(WO3)0.40 55.30  Click
Li 1s (Li2O)41.3(P2O5)53.1(Cr2O3)5.6 55.30  Click
Li 1s (Li2O)(P2O5) 55.30  Click
Li 1s LiNbO3 55.30  Click
Li 1s (F2)0.05((Li2O)0.40(B2O3)0.60)0.95 55.30  Click
Li 1s (F2)0.10((Li2O)0.30(B2O3)0.70)0.90 55.30  Click
Li 1s (Li2O)0.4(B2O3)0.6 55.30  Click
Li 1s Li/Si 55.33  Click
Li 1s Li/Si 55.33  Click
Li 1s Li 55.35  Click
Li 1s O2/Li 55.35  Click
Li 1s (F2)0.10((Li2O)0.50(B2O3)0.50)0.90 55.35  Click
Li 1s Li3PO4 55.40  Click
Li 1s Li4P2O7 55.40  Click
Li 1s Li/CaO 55.40  Click
Li 1s (Li2O)50(P2O5)50 55.40  Click
Li 1s (Li2O)0.50(P2O5)0.05(WO3)0.45 55.40  Click
Li 1s (Li2O)0.50(P2O5)0.50 55.40  Click
Li 1s (Li2O)40(P2O5)30(MoO3)30 55.40  Click
Li 1s (Li2O)50(P2O5)45(MoO3)5 55.40  Click
Li 1s (Li2O)0.50(P2O5)0.40(WO3)0.10 55.40  Click
Li 1s Li/Al 55.40  Click
Li 1s (Li2O)47.3(P2O5)52.7 55.40  Click
Li 1s (Li2O)0.4(B2O3)0.598(Bi2O3)0.002 55.40  Click
Li 1s (F2)0.15((Li2O)0.50(B2O3)0.50)0.85 55.40  Click
Li 1s (LiF)0.40(LiPO3)0.60 55.40  Click
Li 1s (Bi2O3)0.003(LiBO2)0.997 55.40  Click
Li 1s (Bi2O3)0.005(LiBO2)0.995 55.40  Click
Li 1s (Li2O)0.4(B2O3)0.59(Bi2O3)0.01 55.40  Click
Li 1s (Li2O)0.4(B2O3)0.596(Bi2O3)0.004 55.40  Click
Li 1s (Li2O)0.5(B2O3)0.498(Bi2O3)0.002 55.40  Click
Li 1s (Li2O)0.5(B2O3)0.497(Bi2O3)0.003 55.40  Click
Li 1s (Li2O)0.5(B2O3)0.492(Bi2O3)0.008 55.40  Click
Li 1s (Li2O)0.5(B2O3)0.48(Bi2O3)0.02 55.40  Click
Li 1s (Li2O)60(P2O5)40 55.50  Click
Li 1s (Li2O)40(P2O5)42(MoO3)18 55.50  Click
Li 1s (Li2O)50(P2O5)40(MoO3)10 55.50  Click
Li 1s (Li2O)0.50(P2O5)0.15(WO3)0.35 55.50  Click
Li 1s (Li2O)0.50(P2O5)0.20(WO3)0.30 55.50  Click
Li 1s (Li2O)58.8(P2O5)37.1(Cr2O3)4.2 55.50  Click
Li 1s (Li2O)60.4(P2O5)32.0(Cr2O3)7.6 55.50  Click
Li 1s (Li2O)49.5(P2O5)45.5(Cr2O3)5.0 55.50  Click
Li 1s (Li2O)50.5(P2O5)30.4(Cr2O3)19.1 55.50  Click
Li 1s (Li2O)61.7(P2O5)38.3 55.50  Click
Li 1s (LiF)0.18(LiPO3)0.82 55.50  Click
Li 1s (F2)0.30(LiPO3)0.70 55.50  Click
Li 1s (F2)0.40(LiPO3)0.60 55.50  Click
Li 1s (LiF)0.15(LiPO3)0.85 55.50  Click
Li 1s (LiF)0.30(LiPO3)0.70 55.50  Click
Li 1s (LiF)0.35(LiPO3)0.65 55.50  Click
Li 1s (F2)0.20((Li2O)0.30(B2O3)0.70)0.80 55.50  Click
Li 1s (F2)0.20((Li2O)0.50(B2O3)0.50)0.80 55.50  Click
Li 1s (Li2O)0.4(B2O3)0.594(Bi2O3)0.006 55.50  Click
Li 1s (Li2O)0.5(B2O3)0.49(Bi2O3)0.01 55.50  Click
Li 1s (Li2O)0.5(B2O3)0.47(Bi2O3)0.03 55.50  Click
Li 1s (Li2O)0.5(B2O3)0.30(Bi2O3)0.20 55.50  Click
Li 1s Li/Si 55.54  Click
Li 1s Li/Si 55.54  Click
Li 1s (F2)0.25((Li2O)0.30(B2O3)0.70)0.75 55.55  Click
Li 1s (F2)0.05((Li2O)0.50(B2O3)0.50)0.95 55.55  Click
Li 1s (F2)0.10((Li2O)0.40(B2O3)0.60)0.90 55.56  Click
Li 1s Li/Si 55.58  Click
Li 1s Li/Si 55.58  Click
Li 1s Li2O 55.60  Click
Li 1s Li4P2O7 55.60  Click
Li 1s LiCrO2 55.60  Click
Li 1s LiClO4 55.60  Click
Li 1s LiClO4 55.60  Click
Li 1s O2/Li 55.60  Click
Li 1s (Li2O)40(P2O5)60 55.60  Click
Li 1s (Li2O)0.50(P2O5)0.20(WO3)0.30 55.60  Click
Li 1s (Li2O)0.50(P2O5)0.25(WO3)0.25 55.60  Click
Li 1s (Li2O)0.50(P2O5)0.30(WO3)0.20 55.60  Click
Li 1s (Li2O)40.7(P2O5)59.3 55.60  Click
Li 1s (Li2O)40.2(P2O5)35.3(Cr2O3)24.6 55.60  Click
Li 1s (Li2O)51.0(P2O5)39.4(Cr2O3)9.7 55.60  Click
Li 1s (Li2O)51.1(P2O5)36.9(Cr2O3)12.0 55.60  Click
Li 1s (LiF)0.05(LiPO3)0.95 55.60  Click
Li 1s (Li2O)0.30(B2O3)0.70 55.60  Click
Li 1s (F2)0.05((Li2O)0.30(B2O3)0.70)0.95 55.65  Click
Li 1s LiF 55.70  Click
Li 1s LiF 55.70  Click
Li 1s Li/CaO 55.70  Click
Li 1s Li2.74V2O5 55.70  Click
Li 1s O2/Li 55.70  Click
Li 1s (Li2O)40(P2O5)48(MoO3)12 55.70  Click
Li 1s LiB3O5 55.70  Click
Li 1s (Li2O)40.5(P2O5)47.4(Cr2O3)12.1 55.70  Click
Li 1s (Li2O)40.1(P2O5)41.9(Cr2O3)18.0 55.70  Click
Li 1s (F2)0.20(LiPO3)0.80 55.70  Click
Li 1s (F2)0.25(LiPO3)0.75 55.70  Click
Li 1s (F2)0.35(LiPO3)0.65 55.70  Click
Li 1s (LiF)0.10(LiPO3)0.90 55.70  Click
Li 1s (F2)0.30((Li2O)0.30(B2O3)0.70)0.70 55.70  Click
Li 1s Li2SO4 55.75  Click
Li 1s (F2)0.20((Li2O)0.40(B2O3)0.60)0.80 55.75  Click
Li 1s LiCl 55.80  Click
Li 1s LiNO3 55.80  Click
Li 1s (F2)0.15((Li2O)0.30(B2O3)0.70)0.85 55.85  Click
Li 1s (F2)0.15((Li2O)0.40(B2O3)0.60)0.85 55.85  Click
Li 1s O2/Li 55.90  Click
Li 1s (F2)0.25((Li2O)0.40(B2O3)0.60)0.75 55.90  Click
Li 1s Li/CaO 56.00  Click
Li 1s LiCl 56.10  Click
Li 1s Li/Si 56.12  Click
Li 1s Li/Si 56.12  Click
Li 1s Li/Si 56.13  Click
Li 1s Li/Si 56.13  Click
Li 1s Li/Si 56.17  Click
Li 1s Li/Si 56.17  Click
Li 1s LiCl 56.20  Click
Li 1s Li/CaO 56.30  Click
Li 1s LiClO4 56.50  Click
Li 1s LiClO4 56.50  Click
Li 1s Li/Si 56.60  Click
Li 1s Li/Si 56.60  Click
Li 1s Li/Si 56.62  Click
Li 1s Li/Si 56.62  Click
Li 1s Li/Si 56.65  Click
Li 1s Li/Si 56.65  Click
Li 1s LiF 56.70  Click
Li 1s LiBr 56.80  Click
Li 1s LiF 56.80  Click
Li 1s Li/CaO 56.80  Click
Li 1s Li2CrO4 57.10  Click
Li 1s LiC6 57.10  Click
Li 1s LiClO4 57.20  Click
Li 1s LiClO4 57.20  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 Lithium Materials

 

 

 

 

XPS Spectra

 

from Common Lithium Compounds
LiI, LiBr, LiCl, and LiF

                             

Lithium Iodide (LiI):  Li (1s)
C (1s) BE = 285.0 eV
 Lithium Bromide (LiBr):  Li (1s)
C (1s) BE = 285.0 eV
  .
Lithium Chloride (LiCl):  Li (1s)
C (1s) BE = 285.0 eV		 Lithium Fluoride (LiF):  Li (1s)
C (1s) BE = 285.0 eV

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Overlay of:
Li (1s) Spectra – shown above

C (1s) BE = 285.0 eV

→  Periodic Table 

 

 

Lithium Fluoride, LiF
 Fresh exposed bulk produced by cleaving in lab air

F (1s) Energy Loss Satellites  – Extended Range Spectrum F (1s) Energy Loss Satellites – Extended Range Spectrum – Vertically Zoomed

 

. 
Li (1s) or F (2s) Satellites  – Extended Range Spectrum Li (1s) Satellites or F (2s) – Extended Range Spectrum – zoomed

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Valence Band Spectra
LiF, LiCl, LiBr, LiI

Lithium Fluoride, LiF crystal
Charge Referenced so C (1s) = 285.0 eV
 Lithium Chloride, LiCl crystal
Charge Referenced so C (1s) = 285.0 eV

   .
Lithium Bromide, LiBr crystal
Charge Referenced so C (1s) = 285.0 eV		 Lithium Iodide, LiI crystal
Charge Referenced so C (1s) = 285.0 eV

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Overlay of Valence Band Spectra
LiF, LiCl, LiBr, LiI

 
Copyright ©:  The XPS Library

 

AES Chemical State Spectra for LiF (100) Single Crystal
using High Energy Resolution & Charge Control

Survey Spectrum of LiF (cleaved) F KLL Signal of LiF (cleaved)
Tilt Angle: 80, 10 kV beam, Ar+ 500V low curr Tilt Angle: 80, 10 kV beam, Ar+ 500V low curr

.
Li KLL Signal of LiF (cleaved) F KLL Signal – of LiF (cleaved) – Expanded
Tilt Angle: 80, 10 kV beam, Ar+ 500V low curr Tilt Angle: 80, 10 kV beam, Ar+ 500V low curr

 

Li KLL Signal of LiF (cleaved) – First Derivative

  
Tilt Angle: 80, 10 kV beam, Ar+ 500V low curr  
 

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Chemical State Spectra from
Chemical Compounds or Alloys
that include Lithium

 

 

 

LiCoMnNiOx powder

Survey Spectrum of LiCoMnNiOx
   .
Li (1s) Spectrum of LiCoMnNiOx C (1s) Spectrum of LiCoMnNiOx
 
  . 
Mn (2p) Spectrum of LiCoMnNiOx Co (2p) Spectrum of LiCoMnNiOx
 
  . 
Ni (2p) Spectrum of LiCoMnNiOx O (1s) Spectrum of LiCoMnNiOx

 

Copyright ©:  The XPS Library 

 

 

 

XPS Facts, Guidance & Information

→  Periodic Table 

    Element   Lithium (Li)
  
    Primary XPS peak used for Peak-fitting :   Li (1s)  
    Spin-Orbit (S-O) splitting for Primary Peak:   NO Spin-Orbit splitting for “s” orbitals
  
    Binding Energy (BE) of Primary XPS  Signal:   ~55 eV
  
    Scofield Cross-Section (σ) Value:   Li (1s) = 0.0568
  
    Conductivity:   Metal form is Conductive
  
    Range of Li (1s) Chemical State BEs:   55 – 57 eV range   (Lio to LiF)  
    Signals from other elements that overlap
Li (1s) Primary Peak:		   Fe (3p), F (2s) loss peaks  
    Loss Peak:   ~15 eV above peak max for pure metal  
    Shake-up Peaks:   ??  
    Multiplet Splitting Peaks:   ??  

 

 

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

Li metal produces flames if dropped into water and may explode.

  

Copyright ©:  The XPS Library 

 

Information Useful for Peak-fitting Li (1s)

 

  • FWHM (eV) of Li (1s) for LiF (single crystal):  ~1.4 eV using 50 eV Pass Energy (before ion etching)
  • FWHM (eV) of Li (1s) for Li2CO3:  ~1.6 eV using 50 eV Pass Energy  (before ion etching)
  • Binding Energy (BE) of Primary Signal used for Measuring Chemical State Spectra:  55 eV for Li (1s) with +/- 0.2 uncertainty
  • List of XPS Peaks that can Overlap Peak-fit results for Li (1s):  Fe (3p)

→  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.

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 Lithium Compounds

 

  • Lithium metal develops a thick native oxide due to the reactive nature of clean Lithium metal.
  • Lithium 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 Li (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 Lithium (Li)

 

  • Conductivity:  Lithium readily develops a thick oxide in UHV
  • Primary Peak (XPS Signal) used to measure Chemical State Spectra:  Li (1s) at 55 eV
  • Recommended Pass Energy for Measuring Chemical State Spectrum:  40-50eV    (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:  45 – 65 eV
  • Recommended Extended BE Range for Measuring Chemical State Spectrum:  40 – 140 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

  • Pure metal luminesces pink color during 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 
 
 
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