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 – HomePage                    XPS Database of Polymers                  → Six (6) BE Tables



Molybdenum (Mo)

 

Molybdenite – MoS2 Molybdenum – Moo Markascherite – Cu3(MoO4)(OH)4

 

  Page Index
  • Expert Knowledge & Explanations


Molybdenum (Moo) Metal

Peak-fits, BEs, FWHMs, and Peak Labels


  .
Molybdenum (Moo) Metal
Mo (3d) Spectrum – raw spectrum

ion etched clean
Molybdenum (Moo) Metal
Peak-fit of Mo (3d) Spectrum
w/o asymm

 Periodic Table – HomePage  
Molybdenum (Moo) Metal
Mo (3d) Spectrum –
extended range 
Molybdenum (Moo) Metal
Peak-fit of Mo (3d) Spectrum (w asymm)

 .

Molybdenum (Moo) Metal
Mo (3s) Spectrum
Molybdenum (Moo) Metal
Mo (3p) Spectrum

 

 

Survey Spectrum of Molybdenum (Moo) Metal
with Peaks Integrated, Assigned and Labelled

 


 Periodic Table 

XPS Signals for Molybdenum, (Moo) 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
  Mo (3s) 506 2.34 16.4
  Mo (3p1/2) 411 3.04 17.8
N (1s) overlaps Mo (3p3/2) 394 5.94 17.8
  Mo (3d3/2) 231.12 3.88 19.8
S (2s) overlaps Mo (3d5/2) 227.94 5.62 19.8
Na (2s) overlaps Mo (4s) 63 0.44 21.7
  Mo (4p) 36 1.31 22.1

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

Energy Loss Peaks

Auger Peaks

Energy Loss  Peak:  ~xx eV above peak max
Expected Bandgap for MoO3:  3-3.5 eV
Work Function for MoO3:  xx eV

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

 Periodic Table 


 

Valence Band Spectrum from Molybdenum, Moo Metal
 Fresh exposed bulk produced by extensive Ar+ ion etching

 


 

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

Mo (3d) – Extended Range Spectrum Mo (3d) – Extended Range Spectrum – Vertically Zoomed
 Periodic Table 

 

Mo (LMM) Auger Peaks from Moo Metal
 Fresh exposed bulk produced by extensive Ar+ ion etching

Moo Metal – main Auger peak Moo Metal – wide Auger range
 

Features Observed

  • xx
  • xx
  • xx

 Periodic Table 


 

Artefacts Caused by Argon Ion Etching

Molybdenum Carbide(s)

can form when ion etched Reactive Metal Surfaces capture
Residual UHV Gases (CO, H2O, CH4 etc)

Argon Trapped in Moo

can form when Argon Ions are used
to removed surface contamination

na

 

Side-by-Side Comparison of
Mo Native Oxide & Molybdenum Oxide, MoO3
Peak-fits, BEs, FWHMs, and Peak Labels

Mo Native Oxide MoO3
Mo (3d) from Mo Native Oxide
Flood Gun OFF
As-Measured, C (1s) at 284.8 eV 
Mo (3d) from MoO3 – pellet
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 

 Periodic Table 

   
Mo Native Oxide MoO3
C (1s) from Mo Native Oxide
As-Measured, C (1s) at 284.8 eV
Flood Gun OFF

C (1s) from MoO3 – pellet
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 Periodic Table 

 
Mo Native Oxide MoO3
O (1s) from Mo Native Oxide
As-Measured, C (1s) at 284.8 eV
Flood Gun OFF

O (1s) from MoO3 – pellet
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 

 

 Periodic Table

 


 

Survey Spectrum of Molybdenum (Mo) Native Oxide
with Peaks Integrated, Assigned and Labelled

 Periodic Table 


 

 

Survey Spectrum of Molybdenum Oxide (MoO3)
with Peaks Integrated, Assigned and Labelled

 

 

 Periodic Table  


 

Overlays of Mo (3d) Spectra for
Mo Native Oxide and MoO3
Caution: BEs from Grounded Native Oxides can be Misleading if Flood Gun is ON

 

 Overlay of Moo metal and Mo Native Oxide – Mo (3d)
Native Oxide C (1s) = 284.8  (Flood gun OFF)
Chemical Shift: 4.8 eV
 Overlay of Moo metal and MoO3 – Mo (3d)
Pure Oxide C (1s) = 285.0 eV
Chemical Shift: 5.1 eV
 Periodic Table  Copyright ©:  The XPS Library 

 

Overlay of Mo (3d)
Moo Metal, Mo Native Oxide, & MoO3

Features Observed

  • xx
  • xx
  • xx

 Periodic Table 


 

Valence Band Spectra
Moo, MoO3 

Moo
Ion etched clean
MoO3 – pellet
Flood gun is ON,  Charge referenced so C (1s) = 285.0 eV


Overlay of Valence Band Spectra for
Moo metal and MoO3 

Features Observed

  • xx
  • xx
  • xx

 Periodic Table 



 

Molybdenum Minerals, Gemstones, and Chemical Compounds

 

Hoechlinite – Bi2MoO6 Molybdite – MoO3 Wulfenite – Pb(MoO4) Nuragheite – Th(MoO4)2 · H2O

 Periodic Table 



 

 

Six (6) Chemical State Tables of Mo (3d5/2) BEs

 

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

 Periodic Table 



 

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) 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 (3d5/2) 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

Mo (3d5/2) 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 Hydrocarbon C (1s) BE  Source
Mo 42 Mo (N*20) 227.4 eV 228.2 eV 284.8 eV Avg BE – NIST
Mo 42 Mo-Si2 227.4 eV 227.8 eV 285.0 eV The XPS Library
Mo 42 Mo – element 227.8 eV   285.0 eV The XPS Library
Mo 42 Mo2C (N*2) 227.8 eV 228.8 eV 284.8 eV Avg BE – NIST
Mo 42 MoB2 (N*1) 227.9 eV   284.8 eV Avg BE – NIST
Mo 42 Mo2C 228.0 eV 228.3 eV 285.0 eV The XPS Library
Mo 42 Mo-B 228.0 eV   285.0 eV The XPS Library
Mo 42 MoS (N*7) 228.7 eV 229.7 eV 284.8 eV Avg BE – NIST
Mo 42 Mo-O2 (N*12) 228.8 eV 229.7 eV 284.8 eV Avg BE – NIST
Mo 42 Mo-S2 229.2 eV   285.0 eV The XPS Library
Mo 42 MoS2 (N*7) 229.4 eV 230.1 eV 284.8 eV Avg BE – NIST
Mo 42 Mo-Cl3  (N*2) 230.0 eV 230.6 eV 284.8 eV Avg BE – NIST
Mo 42 Mo-Cl5 (N*2) 231.0 eV   284.8 eV Avg BE – NIST
Mo 42 Li2MoO4 (N*1) 232.2 eV   284.8 eV Avg BE – NIST
Mo 42 MoOx ntv (N*10) 232.2 eV 232.8 eV 284.8 eV Avg BE – NIST
Mo 42 MoO3 (N*20) 232.3 eV 232.9 eV 284.8 eV Avg BE – NIST
Mo 42 Na2MoO4-2H2O (N*1) 232.5 eV   284.8 eV Avg BE – NIST
Mo 42 Mo-O3 232.6 eV   285.0 eV The XPS Library
Mo 42 Mo-(OH)2     285.0 eV The XPS Library
Mo 42 Mo-CO3     285.0 eV The XPS Library

Charge Referencing Notes

  • (N*number) identifies the number of NIST BEs that were averaged to produce the BE in the middle column.
  • The XPS Library uses Binding Energy Scale Calibration with Cu (3d5/2) 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

Mo (3d5/2) Chemical State BEs from:  “PHI Handbook”

C (1s) BE = 284.8 eV

 Periodic Table 

Copyright ©:  Ulvac-PHI


Table #3

Mo (3d5/2) Chemical State BEs from:  “Thermo-Scientific” Website

C (1s) BE = 284.8 eV

Chemical state Binding energy (eV),
Mo (3d5/2)
Mo metal 288.0
MoO2 229.5
MoO3 233.1

 Periodic Table 

Copyright ©:  Thermo Scientific 


Table #4

Mo (3d5/2) 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

Mo (3d5/2) 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
Mo 3d5/2 Boride 227.6 ±0.4 227.2 227.9
Mo 3d5/2 (CO)xMo(Ph3P)y 227.6 ±0.4 227.2 227.9
Mo 3d5/2 Mo2C 227.8 ±0.3 227.5 228.0
Mo 3d5/2 Mo 228.0 ±0.3 227.7 228.2
Mo 3d5/2 MoO2 229.4 ±0.4 229.0 229.7
Mo 3d5/2 MoS2 229.4 ±0.4 229.0 229.8
Mo 3d5/2 MoCl3 230.0 ±0.3 229.7 230.3
Mo 3d5/2 MoCl4 230.6 ±0.3 230.3 230.9
Mo 3d5/2 MoCl5 231.0 ±0.2 230.8 231.2
Mo 3d5/2 (NH)4MoO4 232.2 ±0.3 231.9 232.4
Mo 3d5/2 MoO3 232.6 ±0.3 232.3 232.8

 

 Periodic Table 



 


Histograms of NIST BEs for Mo (3d5/2) BEs

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

Histogram indicates:  227.9 eV for Moo based on 21 literature BEs Histogram indicates:  229.7 eV for MoO2 based on 15 literature BEs

 
Histogram indicates:  232.7 eV for MoO3 based on 24 literature BEs

Table #6


NIST Database of Mo (3d5/2) 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
Mo 3d5/2 Mo/Si 224.90  Click
Mo 3d5/2 Mo 226.10  Click
Mo 3d5/2 [Mo(CO)3(P(C6H5O)3)(C10H8N2)] 226.20  Click
Mo 3d5/2 [Mo(CO)4(C10H8N2)] 226.30  Click
Mo 3d5/2 AgMo6S8 226.80  Click
Mo 3d5/2 [Mo(CO)2((C6H5)2PC2H4P(C6H5)2)2] 227.10  Click
Mo 3d5/2 [Mo(CO)2(C10H8N2)(P(C6H5)3)2] 227.10  Click
Mo 3d5/2 Mo2B5 227.30  Click
Mo 3d5/2 [Mo(CO)5(P(C6H5)3)3] 227.40  Click
Mo 3d5/2 [Mo(CO)4(P(C4H9)3)2] 227.40  Click
Mo 3d5/2 [Mo(CO)6(C5H5)2] 227.40  Click
Mo 3d5/2 Mo 227.40  Click
Mo 3d5/2 MoSi2 227.40  Click
Mo 3d5/2 Mo 227.50  Click
Mo 3d5/2 Mo(N2)2((C6H5)2CH2CH2P(C6H5)2)2 227.50  Click
Mo 3d5/2 [Mo(CO)2(CH3CN)(P(C4H9)3)3] 227.60  Click
Mo 3d5/2 [Mo(CO)2(CH3CN)2(P(C6H5)3)2] 227.60  Click
Mo 3d5/2 Mo 227.60  Click
Mo 3d5/2 Mo 227.60  Click
Mo 3d5/2 Mo 227.60  Click
Mo 3d5/2 Lu0.8Pb0.33Mo6S8 227.60  Click
Mo 3d5/2 MoSi2 227.68  Click
Mo 3d5/2 [Mo(CH3CN)(CO)2(CH3P(C6H5)2)3] 227.70  Click
Mo 3d5/2 HoMo6S8 227.70  Click
Mo 3d5/2 PbMo6S8 227.70  Click
Mo 3d5/2 (CH(MoCl2)0.0086)x 227.70  Click
Mo 3d5/2 Mo2C 227.80  Click
Mo 3d5/2 [Mo(CO)4(P(C6H5)3)2] 227.80  Click
Mo 3d5/2 Mo 227.80  Click
Mo 3d5/2 Mo 227.80  Click
Mo 3d5/2 Fe81Cr15Mo4 227.80  Click
Mo 3d5/2 Cr24Fe65Mo11 227.80  Click
Mo 3d5/2 MoSi2.2 227.80  Click
Mo 3d5/2 Mo6S8(C5H5N)6.2(C5H5N) 227.80  Click
Mo 3d5/2 MoB2 227.90  Click
Mo 3d5/2 Mo 227.90  Click
Mo 3d5/2 Mo 227.90  Click
Mo 3d5/2 InMo6S8 227.90  Click
Mo 3d5/2 Lu1.2Mo6S8 227.90  Click
Mo 3d5/2 Mo/Si 227.90  Click
Mo 3d5/2 Cr/MoS2 227.90  Click
Mo 3d5/2 Mo6S8(C4H9N)6.(C4H9N) 227.90  Click
Mo 3d5/2 Mo6S8(C4H8S)6 227.90  Click
Mo 3d5/2 Mo6S8(C3H7NH2)6-x 227.90  Click
Mo 3d5/2 Mo6S8(C5H11N)6.7(C5H11N) 227.90  Click
Mo 3d5/2 Mo 227.92  Click
Mo 3d5/2 Mo 227.94  Click
Mo 3d5/2 Mo 227.95  Click
Mo 3d5/2 [Mo2Cl4(C4H4N2)2] 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo 228.00  Click
Mo 3d5/2 Mo6Se8(P(C2H5)3)6 228.00  Click
Mo 3d5/2 Mo6S8(P(C2H5)3)6 228.00  Click
Mo 3d5/2 PbMo6.2S8 228.00  Click
Mo 3d5/2 Mo6S8(P(C2H5)3)6 228.00  Click
Mo 3d5/2 GaMo4S4Te4 228.00  Click
Mo 3d5/2 Mo 228.10  Click
Mo 3d5/2 B/Mo 228.10  Click
Mo 3d5/2 MoN0.17 228.10  Click
Mo 3d5/2 MoN 228.10  Click
Mo 3d5/2 Cr/MoS2 228.10  Click
Mo 3d5/2 Cr/MoS2 228.10  Click
Mo 3d5/2 Mo 228.20  Click
Mo 3d5/2 [Mo(CO)5Clr(P(C6H5)4)] 228.20  Click
Mo 3d5/2 C/Mo 228.20  Click
Mo 3d5/2 Mo(CO)5(C5H4P(C6H5)2)2Fe 228.20  Click
Mo 3d5/2 Cr/MoS2 228.20  Click
Mo 3d5/2 Cr/MoS2 228.20  Click
Mo 3d5/2 Cr/MoS2 228.20  Click
Mo 3d5/2 Mo2N 228.20  Click
Mo 3d5/2 [Mo(CO)5(As(C6H5)3)] 228.29  Click
Mo 3d5/2 [MoI(CO)2(C3H5)(NC5H4C5H4N)] 228.30  Click
Mo 3d5/2 [Mo(CO)5(P(C6H5)3)] 228.30  Click
Mo 3d5/2 SnMo6S8 228.30  Click
Mo 3d5/2 MoSe2 228.30  Click
Mo 3d5/2 MoO3 228.30  Click
Mo 3d5/2 CO/Mo 228.30  Click
Mo 3d5/2 O2/Mo 228.30  Click
Mo 3d5/2 O2/Mo 228.30  Click
Mo 3d5/2 Lu0.1PbMo6S8 228.30  Click
Mo 3d5/2 Lu0.4Pb0.67Mo6S8 228.30  Click
Mo 3d5/2 Mo(CO)5(C5H4P(C6H5)2)2FeMo(CO)5 228.30  Click
Mo 3d5/2 Fe(CO)4(C5H4P(C6H5)2)2FeMo(CO)5 228.30  Click
Mo 3d5/2 Cr/MoS2 228.30  Click
Mo 3d5/2 Li2.9MoO1.6S1.9 228.30  Click
Mo 3d5/2 GaMo4S8 228.30  Click
Mo 3d5/2 [Mo(CO)3(C7H8)] 228.40  Click
Mo 3d5/2 [N(C2H5)4][Mo(CO)5Cl] 228.40  Click
Mo 3d5/2 O2/Mo 228.40  Click
Mo 3d5/2 MoN0.17 228.40  Click
Mo 3d5/2 MoN 228.40  Click
Mo 3d5/2 Cr/MoS2 228.40  Click
Mo 3d5/2 Li2.00MoS3 228.40  Click
Mo 3d5/2 Li1.60MoS3 228.40  Click
Mo 3d5/2 MoN1.5 228.40  Click
Mo 3d5/2 Ti0.2Mo0.8N 228.45  Click
Mo 3d5/2 [Mo(CO)5(Sb(C6H5)3)] 228.48  Click
Mo 3d5/2 [MoCl(CO)2(C3H5)(NC5H4C5H4N)] 228.50  Click
Mo 3d5/2 [Mo(CO)3(C5H5)(Sn(CH3)3)] 228.50  Click
Mo 3d5/2 [Mo(CO)5Br(P(C6H5)4)] 228.50  Click
Mo 3d5/2 MoS2 228.50  Click
Mo 3d5/2 O2/Mo 228.50  Click
Mo 3d5/2 MoWCl4(P(CH3)3)4 228.50  Click
Mo 3d5/2 Mo4S4Cl4 228.50  Click
Mo 3d5/2 [MoBr(CO)2(C3H5)(NC5H4C5H4N)] 228.60  Click
Mo 3d5/2 [Mo2Cl4(CH3(C4H2N2)CH3)4] 228.60  Click
Mo 3d5/2 Mo 228.60  Click
Mo 3d5/2 Mo5As4 228.60  Click
Mo 3d5/2 [Mo2Cl4((C5H5N)NHCH3)2] 228.70  Click
Mo 3d5/2 [Mo(CO)3(ClSn(CH3)2)(C5H5)] 228.70  Click
Mo 3d5/2 [Mo2Cl4(P(C2H5)3)4] 228.70  Click
Mo 3d5/2 [Mo2Cl4(CH3P(C6H5)2)4] 228.70  Click
Mo 3d5/2 [MoCl(CO)2((C6H5)2PCH2CH2P(C6H5)2)(C3H5)] 228.70  Click
Mo 3d5/2 CoMo2S4 228.70  Click
Mo 3d5/2 Ga2Mo5As4 228.70  Click
Mo 3d5/2 Li0.96MoS3 228.70  Click
Mo 3d5/2 [Mo(CO)2(C5H5)(NC(CH3C6H4)2)] 228.80  Click
Mo 3d5/2 [Mo(CO)3Cl2(P(C6H5)3)2] 228.80  Click
Mo 3d5/2 (Mo6I8)I4 228.80  Click
Mo 3d5/2 MoO2 228.80  Click
Mo 3d5/2 MoS2 228.80  Click
Mo 3d5/2 [Mo3Ni2Se4Cl4{P(C2H5)3}5] 228.80  Click
Mo 3d5/2 MoS2 228.80  Click
Mo 3d5/2 MoS2 228.80  Click
Mo 3d5/2 Mo2C 228.80  Click
Mo 3d5/2 Cu4Mo5As4 228.80  Click
Mo 3d5/2 MoS1.97 228.80  Click
Mo 3d5/2 [MoBr(NNH2)((C6H5)2CH2CH2P(C6H5)2)2]Br 228.80  Click
Mo 3d5/2 [Mo2Cl4(C5H5N)4] 228.90  Click
Mo 3d5/2 MoO2 228.90  Click
Mo 3d5/2 MoS2 228.90  Click
Mo 3d5/2 [Mo3Ni2S4Cl4{P(C2H5)3}5] 228.90  Click
Mo 3d5/2 O2/Mo 228.90  Click
Mo 3d5/2 MoN0.17 228.95  Click
Mo 3d5/2 MoN 228.95  Click
Mo 3d5/2 [N(C4H9)4]2[Mo4I11] 229.00  Click
Mo 3d5/2 MoS2 229.00  Click
Mo 3d5/2 MoS2 229.00  Click
Mo 3d5/2 (C5H6N)4[Mo3S4(NCS)8(H2O)].4H2O 229.00  Click
Mo 3d5/2 (CH(MoCl2)0.0086)x 229.00  Click
Mo 3d5/2 Mo2Cl4(P(CH3)3)4 229.00  Click
Mo 3d5/2 Cr/MoS2 229.00  Click
Mo 3d5/2 Cr/MoS2 229.00  Click
Mo 3d5/2 [Mo(CO)3(C7H7)].BF4 229.10  Click
Mo 3d5/2 MoO2 229.10  Click
Mo 3d5/2 MoS2 229.10  Click
Mo 3d5/2 Cr/MoS2 229.10  Click
Mo 3d5/2 Cr/MoS2 229.10  Click
Mo 3d5/2 Cr/MoS2 229.10  Click
Mo 3d5/2 [Mo(CO)3(Sn(C6H5)3)(C5H5)] 229.20  Click
Mo 3d5/2 K4Mo2Cl8 229.20  Click
Mo 3d5/2 [Mo(CO)2(C3H5)(C5H5N)(OC(CH3)CHC(CH3)O)] 229.20  Click
Mo 3d5/2 [N(C2H5)4]2[Mo6Br8Cl6] 229.20  Click
Mo 3d5/2 MoS2 229.20  Click
Mo 3d5/2 MoS2 229.20  Click
Mo 3d5/2 MoO2 229.20  Click
Mo 3d5/2 Cr/MoS2 229.20  Click
Mo 3d5/2 MoS3 229.20  Click
Mo 3d5/2 [Mo3FeS4(H2O)(NH3)9]Cl4 229.20  Click
Mo 3d5/2 (NH4)2[Mo3S13].H2O 229.20  Click
Mo 3d5/2 [MoCl2(CO)2(P(C6H5)3)2] 229.30  Click
Mo 3d5/2 [Mo(SnCl3)(CO)3(C5H5)] 229.30  Click
Mo 3d5/2 (Mo6Br8)Br4 229.30  Click
Mo 3d5/2 [Mo6Cl8Cl4(SO(CH3)2)2] 229.30  Click
Mo 3d5/2 [N(C2H5)4]2[Mo6Br8Br6] 229.30  Click
Mo 3d5/2 [Mo6Br8(P(C3H7)3)2]Br4 229.30  Click
Mo 3d5/2 MoO2 229.30  Click
Mo 3d5/2 MoO2 229.30  Click
Mo 3d5/2 MoO2 229.30  Click
Mo 3d5/2 MoO2 229.30  Click
Mo 3d5/2 (C5H6N)5[Mo3OS3(NCS)9].2H2O 229.30  Click
Mo 3d5/2 Cr/MoS2 229.30  Click
Mo 3d5/2 MoS3 229.30  Click
Mo 3d5/2 [MoCl3(P(CH3)2C6H5)3] 229.40  Click
Mo 3d5/2 MoO2 229.40  Click
Mo 3d5/2 MoS2 229.40  Click
Mo 3d5/2 (C5H6N)5[Mo3O2S2(NCS)9].2H2O 229.40  Click
Mo 3d5/2 [MoCl3(C5H5N)3] 229.50  Click
Mo 3d5/2 [N(C4H9)4]3[Mo2Cl9] 229.50  Click
Mo 3d5/2 MoO2 229.50  Click
Mo 3d5/2 MoS2 229.50  Click
Mo 3d5/2 MoS2 229.50  Click
Mo 3d5/2 MoS2 229.50  Click
Mo 3d5/2 Mo(CO)6/Si 229.50  Click
Mo 3d5/2 MoS3 229.50  Click
Mo 3d5/2 MoOOH 229.50  Click
Mo 3d5/2 [Mo6Cl8Cl4(C5H5N)2] 229.60  Click
Mo 3d5/2 [Mo6Cl8Cl4(P(C6H5)3)2] 229.60  Click
Mo 3d5/2 MoO2 229.60  Click
Mo 3d5/2 (C5H6N)5[Mo3O3S(NCS)9].2H2O 229.60  Click
Mo 3d5/2 MoCl3(P(CH3)2C6H5)3 229.60  Click
Mo 3d5/2 MoO0.6S1.9 229.60  Click
Mo 3d5/2 MoO1.0S2.0 229.60  Click
Mo 3d5/2 K4[Mo(CN)8] 229.70  Click
Mo 3d5/2 [Mo6Br8(C5H5N)2]Br4 229.70  Click
Mo 3d5/2 MoO2 229.70  Click
Mo 3d5/2 MoS2 229.70  Click
Mo 3d5/2 MoS2 229.70  Click
Mo 3d5/2 MoS2 229.70  Click
Mo 3d5/2 MoO1.6S1.9 229.70  Click
Mo 3d5/2 LiMoO1.6S1.9 229.70  Click
Mo 3d5/2 MoO0.5S2.0 229.70  Click
Mo 3d5/2 MoO1.6S1.6 229.70  Click
Mo 3d5/2 Li2.9MoO1.6S1.9 229.70  Click
Mo 3d5/2 MoS2 229.76  Click
Mo 3d5/2 MoO2 229.80  Click
Mo 3d5/2 Li0.5MoO1.6S1.9 229.80  Click
Mo 3d5/2 [Mo3FeS4(H2O)10](CH3C6H4SO3)4.7H2O 229.80  Click
Mo 3d5/2 (MoO3)0.90(Fe2O3)0.10 229.90  Click
Mo 3d5/2 MoCl3 230.00  Click
Mo 3d5/2 MoO2 230.00  Click
Mo 3d5/2 [Mo3FeS4(H2O)10](SO3C6H4CH3)4.7H2O 230.00  Click
Mo 3d5/2 [Mo3InS4(SO3C6H4CH3)2(H2O)10](SO3C6H4CH3)3.13H2O 230.00  Click
Mo 3d5/2 WMo2NiS8O29C28H62 230.00  Click
Mo 3d5/2 MoS2 230.02  Click
Mo 3d5/2 ((C6H5)4P)2[Mo2O2S2(S2)(S4)] 230.10  Click
Mo 3d5/2 MoOCl2(P(CH3)2C6H5)3 230.10  Click
Mo 3d5/2 [Mo3NiS4(H2O)10](SO3C6H4CH3)4.7H2O 230.10  Click
Mo 3d5/2 [Mo3NiS4(H2O)10](CH3C6H4SO3)4.7H2O 230.10  Click
Mo 3d5/2 MoS2 230.11  Click
Mo 3d5/2 MoS2 230.12  Click
Mo 3d5/2 Mo2(OH)5OC2H5 230.20  Click
Mo 3d5/2 (NH4)2MoS4 230.20  Click
Mo 3d5/2 [MoCl2(NO)2((C6H5)3P)2] 230.30  Click
Mo 3d5/2 MoW2S4(H2O)9(CH3C6H4SO3)4.9H2O 230.30  Click
Mo 3d5/2 [Mo(NO)2Cl2] 230.40  Click
Mo 3d5/2 Mo2WS4(H2O)9(CH3C6H4SO3)4.9H2O 230.40  Click
Mo 3d5/2 (MoO3)0.10(Fe2O3)0.90 230.40  Click
Mo 3d5/2 (MoO3)0.30(Fe2O3)0.70 230.40  Click
Mo 3d5/2 Na2[Mo2(O)2(muS)2(mu(O(O)CCH2)2NCH2CH2N(CH2C(O)O))] 230.50  Click
Mo 3d5/2 Na2[Mo2(O)2(muO)(muS)(mu(O(O)CCH2)2NCH2CH2N(CH2C(O)O))] 230.50  Click
Mo 3d5/2 Mo3S4(H2O)9(CH3C6H4SO3)4.9H2O 230.50  Click
Mo 3d5/2 [Mo3S4(H2O)9](SO3-C6H4-CH3)4.9H2O 230.50  Click
Mo 3d5/2 [Mo3S4(H2O)9](CH3C6H4SO3)4.9H2O 230.50  Click
Mo 3d5/2 (MoO3)0.50(Fe2O3)0.50 230.50  Click
Mo 3d5/2 MoCl3 230.60  Click
Mo 3d5/2 MoCl4 230.60  Click
Mo 3d5/2 [MoW2O2(CH3C(O)O)6(H2O)3]Br2 230.60  Click
Mo 3d5/2 ((C2H5)4N)2[Mo2O2S2(S2)(S4)] 230.60  Click
Mo 3d5/2 MoO0.6S1.9 230.70  Click
Mo 3d5/2 [MoCl4(C5H5N)2] 230.80  Click
Mo 3d5/2 [Mo2WO2(CH3C(O)O)6(H2O)3]Br2 230.80  Click
Mo 3d5/2 MoO1.0S2.0 230.80  Click
Mo 3d5/2 MoO2 230.90  Click
Mo 3d5/2 MoO1.6S1.6 230.90  Click
Mo 3d5/2 (MoO3)0.70(Fe2O3)0.30 230.90  Click
Mo 3d5/2 (MoO3)0.95(Fe2O3)0.05 230.90  Click
Mo 3d5/2 MoCl5 231.00  Click
Mo 3d5/2 MoCl5 231.00  Click
Mo 3d5/2 MoCl5 231.00  Click
Mo 3d5/2 MoO1.6S1.9 231.00  Click
Mo 3d5/2 Li2.9MoO1.6S1.9 231.00  Click
Mo 3d5/2 MoO2 231.10  Click
Mo 3d5/2 Mo(OH)x/Mo 231.10  Click
Mo 3d5/2 LiMoO1.6S1.9 231.10  Click
Mo 3d5/2 Li0.5MoO1.6S1.9 231.10  Click
Mo 3d5/2 Mo4O11 231.23  Click
Mo 3d5/2 [Mo3O2(CH3C(O)O)6(H2O)3]Br2 231.30  Click
Mo 3d5/2 Na2[Mo(O)W(O)(muO)2(mu(O(O)C)2NCH2CH2N(C(O)O)2)] 231.30  Click
Mo 3d5/2 Na2[Mo(O)W(O)(muO)2(mu(O(O)CCH2)2NCH2CH2N(CH2C(O)O))] 231.30  Click
Mo 3d5/2 [MoCl3(CH3CN)2(NO)2] 231.50  Click
Mo 3d5/2 [IrC5(CH3)5MoO4]4 231.50  Click
Mo 3d5/2 (NH4)2[Mo3O4(C2O4)3(H2O)3] 231.50  Click
Mo 3d5/2 (NH4)2[Mo3O4(C2O4)3(H2O)3] 231.50  Click
Mo 3d5/2 [N(C4H9)4]3PMo3W9O39 231.50  Click
Mo 3d5/2 (N(C4H9)4)3PMo12O38 231.50  Click
Mo 3d5/2 (C5H6N)5[Mo3O4(NCS)9].H2O 231.60  Click
Mo 3d5/2 [RhC5(CH3)5MoO4]4.2H2O 231.60  Click
Mo 3d5/2 Na2[Mo(O)Mo(O)(muO)(muO)(mu(O(O)CCH2)2NCH2CH2N(CH2C(O)O)2)] 231.70  Click
Mo 3d5/2 Na2[Mo(O)Mo(O)(muO)(muO)(mu(O(O)CCH2)2NCH2CH2N(CH2C(O)O)2)] 231.70  Click
Mo 3d5/2 MoO3/C 231.70  Click
Mo 3d5/2 Na2MoO4.2H2O 231.70  Click
Mo 3d5/2 (N(C4H9)4)3PMo12O39 231.70  Click
Mo 3d5/2 [MoOBr4(As(C6H5)4)] 231.80  Click
Mo 3d5/2 Rh2MoO6 231.80  Click
Mo 3d5/2 (MoO3)70(SiO)30 231.80  Click
Mo 3d5/2 (N(C2H5)4)2[Mo6O19] 231.80  Click
Mo 3d5/2 Mo4O11 231.83  Click
Mo 3d5/2 MoOx 231.90  Click
Mo 3d5/2 [MoCl3(O2)(C10H8N2)] 231.90  Click
Mo 3d5/2 [MoCl4(P(C6H5)3)2] 231.90  Click
Mo 3d5/2 Na2MoO4 231.90  Click
Mo 3d5/2 MoO3/TiO2 231.90  Click
Mo 3d5/2 (MoO2)16.Na56(Al2O3)56(SiO2)136.xH20 231.90  Click
Mo 3d5/2 Mo4O11 231.93  Click
Mo 3d5/2 [MoCl4(O2)(C10H8N2)] 232.00  Click
Mo 3d5/2 [Mo(O)2(CH3C(O)CHC(O)CH3)2] 232.00  Click
Mo 3d5/2 MoO2 232.00  Click
Mo 3d5/2 Na2MoO4 232.00  Click
Mo 3d5/2 Na2MoO4 232.00  Click
Mo 3d5/2 Na2MoO4 232.00  Click
Mo 3d5/2 MoO3/(SiO2+Al2O3) 232.00  Click
Mo 3d5/2 (MoO3)70(SiO)30 232.00  Click
Mo 3d5/2 Na2MoO4 232.00  Click
Mo 3d5/2 (MoO3)50(SiO)50 232.00  Click
Mo 3d5/2 Na2MoO4 232.00  Click
Mo 3d5/2 (NH4)2[Mo2O4(C4H4O6)2(H2O)2] 232.00  Click
Mo 3d5/2 Mo4O11 232.06  Click
Mo 3d5/2 (NH4)2MoO4 232.10  Click
Mo 3d5/2 K2MoO4 232.10  Click
Mo 3d5/2 Na2MoO4 232.10  Click
Mo 3d5/2 MoS2 232.10  Click
Mo 3d5/2 MoO3/SiO2 232.10  Click
Mo 3d5/2 MoO3 232.10  Click
Mo 3d5/2 (MoO3)60(SiO)40 232.10  Click
Mo 3d5/2 MoOx 232.18  Click
Mo 3d5/2 Li2MoO4 232.20  Click
Mo 3d5/2 MoO3 232.20  Click
Mo 3d5/2 CrMoO4 232.20  Click
Mo 3d5/2 (MoO3)70(SiO)30 232.20  Click
Mo 3d5/2 (MoO3)70(SiO)30 232.20  Click
Mo 3d5/2 (N2H5)2[Mo2O4(OH)4(H2O)2] 232.20  Click
Mo 3d5/2 (N2H5)2[Mo2O4(OH)4(H2O)2] 232.20  Click
Mo 3d5/2 (N2H5)2[Mo2O4(C2O4)2(H2O)2] 232.20  Click
Mo 3d5/2 (N2H5)2[Mo2O4(C2O4)2(H2O)2] 232.20  Click
Mo 3d5/2 [MoCl2(O2)(C10H8N2)] 232.30  Click
Mo 3d5/2 [MoCl3(O)(P(C6H5)3)2] 232.30  Click
Mo 3d5/2 MoO3 232.30  Click
Mo 3d5/2 MoO3 232.30  Click
Mo 3d5/2 CoMoO4 232.30  Click
Mo 3d5/2 CoMoO4 232.30  Click
Mo 3d5/2 Na2MoO4 232.30  Click
Mo 3d5/2 (MoO3)80(SiO)20 232.30  Click
Mo 3d5/2 (NH4)6Mo7O24 232.30  Click
Mo 3d5/2 MoOx 232.40  Click
Mo 3d5/2 Cu2Mo3O10 232.40  Click
Mo 3d5/2 Ce2(MoO4)3 232.40  Click
Mo 3d5/2 MoO3 232.40  Click
Mo 3d5/2 MoO3 232.40  Click
Mo 3d5/2 CoMoO4 232.40  Click
Mo 3d5/2 UO2MoO4 232.40  Click
Mo 3d5/2 MoO3 232.40  Click
Mo 3d5/2 MoO3 232.40  Click
Mo 3d5/2 MoO3 232.40  Click
Mo 3d5/2 Ba8Mo20O65(OH)6.12H2O 232.40  Click
Mo 3d5/2 C18H12S12[Mo6O19] 232.40  Click
Mo 3d5/2 (Li2O)40(P2O5)18(MoO3)42 232.40  Click
Mo 3d5/2 MoOx 232.41  Click
Mo 3d5/2 Na2MoO4.2H2O 232.50  Click
Mo 3d5/2 (NH4)2Mo2O7 232.50  Click
Mo 3d5/2 Al2(MoO4)3 232.50  Click
Mo 3d5/2 MoO3 232.50  Click
Mo 3d5/2 MoO3 232.50  Click
Mo 3d5/2 MoO3 232.50  Click
Mo 3d5/2 CoMoO4 232.50  Click
Mo 3d5/2 NiMoO4 232.50  Click
Mo 3d5/2 Na2MoO4 232.50  Click
Mo 3d5/2 MoO3 232.50  Click
Mo 3d5/2 MoO3 232.50  Click
Mo 3d5/2 MoO3/Al2O3 232.50  Click
Mo 3d5/2 (MoO3)90(SiO)10 232.50  Click
Mo 3d5/2 Ce2(MoO4)3O 232.52  Click
Mo 3d5/2 MoOx 232.55  Click
Mo 3d5/2 Ce2Mo4O15 232.55  Click
Mo 3d5/2 Mo4O11 232.57  Click
Mo 3d5/2 MoO3 232.60  Click
Mo 3d5/2 MoO3 232.60  Click
Mo 3d5/2 MoO3 232.60  Click
Mo 3d5/2 O2/Cr24Fe65Mo11 232.60  Click
Mo 3d5/2 (MoO3)23.75(TeO2)5(V2O5)71.25 232.60  Click
Mo 3d5/2 (Li2O)50(P2O5)25(MoO3)25 232.60  Click
Mo 3d5/2 C12H8S8[Mo6O19] 232.60  Click
Mo 3d5/2 (NH4)4[Ni(OH)6Mo6O18].5H2O 232.60  Click
Mo 3d5/2 Li2.00MoS3 232.60  Click
Mo 3d5/2 Li1.60MoS3 232.60  Click
Mo 3d5/2 MoOx 232.62  Click
Mo 3d5/2 Ce8Mo12O49 232.62  Click
Mo 3d5/2 Mo4O11 232.64  Click
Mo 3d5/2 MoOx 232.65  Click
Mo 3d5/2 MoOx 232.70  Click
Mo 3d5/2 [NH4]2[Mo7O24].4H2O 232.70  Click
Mo 3d5/2 Al2(MoO4)3 232.70  Click
Mo 3d5/2 Bi2(MoO4)3 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 CuMoO4 232.70  Click
Mo 3d5/2 CoMo/Al2O3 232.70  Click
Mo 3d5/2 (MoO3)46(P2O5)54 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 (MoO3)25(V2O5)75 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 (MoO3)22.5(TeO2)10(V2O5)67.5 232.70  Click
Mo 3d5/2 (Li2O)40(P2O5)24(MoO3)36 232.70  Click
Mo 3d5/2 (Li2O)50(P2O5)30(MoO3)20 232.70  Click
Mo 3d5/2 MoO1.6S1.9 232.70  Click
Mo 3d5/2 (N(C4H9)4)3PMo12O40 232.70  Click
Mo 3d5/2 LiMoO1.6S1.9 232.70  Click
Mo 3d5/2 Bi2MoO6 232.70  Click
Mo 3d5/2 MoO0.6S1.9 232.70  Click
Mo 3d5/2 MoO1.0S2.0 232.70  Click
Mo 3d5/2 MoO3.1S0.1 232.70  Click
Mo 3d5/2 Li0.5MoO1.6S1.9 232.70  Click
Mo 3d5/2 Li2.9MoO1.6S1.9 232.70  Click
Mo 3d5/2 MoO3 232.70  Click
Mo 3d5/2 MoO3 232.71  Click
Mo 3d5/2 MoOx 232.74  Click
Mo 3d5/2 MoOx 232.75  Click
Mo 3d5/2 MoO3 232.75  Click
Mo 3d5/2 Mo4O11 232.75  Click
Mo 3d5/2 MoO3/Si 232.75  Click
Mo 3d5/2 MoO3/Pt 232.75  Click
Mo 3d5/2 MoOx 232.80  Click
Mo 3d5/2 MoO3 232.80  Click
Mo 3d5/2 MoO3 232.80  Click
Mo 3d5/2 CaMoO4 232.80  Click
Mo 3d5/2 Bi2MoO6 232.80  Click
Mo 3d5/2 Cu3Mo2O9 232.80  Click
Mo 3d5/2 Bi2Mo2O9 232.80  Click
Mo 3d5/2 (NH4)6Mo7O24.4H2O 232.80  Click
Mo 3d5/2 MoO3/Mo/Al 232.80  Click
Mo 3d5/2 CoMoO4 232.80  Click
Mo 3d5/2 MoO3 232.80  Click
Mo 3d5/2 MoO3 232.80  Click
Mo 3d5/2 MoO3 232.80  Click
Mo 3d5/2 MoO3 232.80  Click
Mo 3d5/2 (Li2O)40(P2O5)30(MoO3)30 232.80  Click
Mo 3d5/2 (Li2O)50(P2O5)45(MoO3)5 232.80  Click
Mo 3d5/2 (Li2O)60(P2O5)36(MoO3)4 232.80  Click
Mo 3d5/2 (N(C4H9)4)3PMo12O38 232.80  Click
Mo 3d5/2 MoO1.6S1.6 232.80  Click
Mo 3d5/2 Na0.03(NiMoO4)0.97 232.80  Click
Mo 3d5/2 K0.03(NiMoO4)0.97 232.80  Click
Mo 3d5/2 Mo(O)2O2(ClC6H4CH2NH2)2 232.80  Click
Mo 3d5/2 Li0.03(NiMoO4)0.97 232.80  Click
Mo 3d5/2 MoO3 232.85  Click
Mo 3d5/2 MoO3 232.85  Click
Mo 3d5/2 MoO3 232.90  Click
Mo 3d5/2 (MoO3)56(P2O5)44 232.90  Click
Mo 3d5/2 MoO3 232.90  Click
Mo 3d5/2 MoO3 232.90  Click
Mo 3d5/2 (Li2O)50(P2O5)35(MoO3)15 232.90  Click
Mo 3d5/2 (Li2O)50(P2O5)40(MoO3)10 232.90  Click
Mo 3d5/2 H2V12-xMoxO31-y.nH2O 232.90  Click
Mo 3d5/2 (N(C4H9)4)3PMo12O39 232.90  Click
Mo 3d5/2 Cs0.03(NiMoO4)0.97 232.90  Click
Mo 3d5/2 MoO3 232.99  Click
Mo 3d5/2 Bi2(MoO4)3 233.00  Click
Mo 3d5/2 MoO3 233.00  Click
Mo 3d5/2 (Li2O)40(P2O5)36(MoO3)24 233.00  Click
Mo 3d5/2 NiMoO4 233.00  Click
Mo 3d5/2 NiMoO4 233.00  Click
Mo 3d5/2 MoO3 233.02  Click
Mo 3d5/2 MoO3 233.10  Click
Mo 3d5/2 MoO3 233.10  Click
Mo 3d5/2 CoMoO4 233.10  Click
Mo 3d5/2 (MoO3)68(P2O5)32 233.10  Click
Mo 3d5/2 MoO3 233.10  Click
Mo 3d5/2 MoO3 233.10  Click
Mo 3d5/2 [N(C4H9)4]3PMo3W9O39 233.10  Click
Mo 3d5/2 MoO3 233.10  Click
Mo 3d5/2 CoMoO4 233.15  Click
Mo 3d5/2 MoO3 233.15  Click
Mo 3d5/2 MoO3 233.20  Click
Mo 3d5/2 (Li2O)40(P2O5)42(MoO3)18 233.20  Click
Mo 3d5/2 (Li2O)40(P2O5)54(MoO3)6 233.20  Click
Mo 3d5/2 [N(C4H9)4]3PMo3W9O40 233.20  Click
Mo 3d5/2 MoO3 233.25  Click
Mo 3d5/2 Al2(MoO4)3 233.30  Click
Mo 3d5/2 Mo4O11 233.35  Click
Mo 3d5/2 MoO3 233.40  Click
Mo 3d5/2 (Li2O)40(P2O5)48(MoO3)12 233.40  Click
Mo 3d5/2 MoO2(C5H7O2)2 233.40  Click
Mo 3d5/2 MoO3 233.50  Click
Mo 3d5/2 MoO3 233.60  Click
Mo 3d5/2 (MoO3)0.995(Fe2O3)0.005 233.60  Click
Mo 3d5/2 NiMoO4 233.70  Click
Mo 3d5/2 NiMoO4 233.70  Click
Mo 3d5/2 (MoO3)16.Na56(Al2O3)56(SiO2)136.xH20 233.80  Click
Mo 3d5/2 Li0.96MoS3 233.80  Click

 

 

Statistical Analysis of Binding Energies in NIST XPS Database of BEs

 

 

 Periodic Table 


 

Advanced XPS Information Section

Expert Knowledge, Spectra, Features, Guidance and Cautions
for XPS Research Studies on Molybdenum Materials

 

 


 

Expert Knowledge Explanations

 Periodic Table 


 

 

Molybdenum Chemical Compounds


Peak-fits and Overlays of Chemical State Spectra

Pure Molybdenum, Moo:  Mo (3d)
Cu (2p3/2) BE = 932.6 eV
MoO3:  Mo (3d)
C (1s) BE = 285.0 eV
MoS2:  Mo (3d)
Conductive – no carbon signal

Features Observed

  • xx
  • xx
  • xx

 Periodic Table 


 

Overlay of Mo (3d) Spectra shown Above

C (1s) BE = 285.0 eV

 

Chemical Shift between Mo and MoO3:  5.1 eV
 Chemical Shift between Mo and MoS2:  1.1 eV

 

 Periodic Table 


 

 

Molybdenum Oxide (MoO3)
pressed pellet 

Survey Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV
Mo (3d) Chemical State Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV

 
O (1s) Chemical State Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV
C (1s) Chemical State Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV

 
Mo (4p) Chemical State Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV
Mo (3p3/2) Chemical State Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV

 
Valence Band Spectrum from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV
Auger Signals from MoO3
Flood gun is ON, C (1s) BE = 285.0 eV
na

Features Observed

  • xx
  • xx
  • xx

 Periodic Table 

 


 


Molybdenum Chemical Compounds

 

Molybdenum Sulfide, MoS2
Molybdenite

Survey Spectrum Mo (3d) Spectrum


 
S (2p) Spectrum Valence Band Spectrum


 
Mo (4p) Spectrum Mo (4p) Spectrum
   

 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.

 

Quantitation from Pure, Homogeneous Binary Compound
composed of Molybdenum – MoO3

This section is focused on measuring and reporting the atom % quantitation that results by using:

  • Scofield cross-sections,
  • Spectra corrected to be free from Transmission Function effects
  • A Pass Energy that does not saturate the detector system in the low KE range (BE = 1000-1400 eV)
  • A focused beam of X-ray smaller than the field of view of the lens
  • An angle between the lens and the source that is ~55 deg that negates the effects of beta-asymmetry
  • TPP-2M inelastic mean free path values, and
  • Either a linear background or an iterated Shirley (Sherwood-Proctor) background to define peak areas

The results show here are examples of a method being developed that is expected to improve the “accuracy” or “reliability” of the atom % values produced by XPS.

 

 Periodic Table 

 


 

 

Flood Gun Effect on Native Oxide of Molybdenum

 

Native Oxide of Molybdenum Sheet – Sample GROUNDED
versus
Native Oxide of Molybdenum Sheet – Sample FLOATING

 


 

Native Oxide of Molybdenum Sheet – Sample Grounded

Electron Flood Gun:  0 Voltage (FG OFF), Min Voltage versus Max Voltage

Mo (3d) O (1s) C (1s)
     
 Periodic Table     

 

Native Oxide of Molybdenum Sheet – Sample Floating

Electron Flood Gun:  0 Voltage (FG OFF), Min Voltage versus Max Voltage

Mo (3d) O (1s) C (1s)
     
     

 Periodic Table 

 


 

XPS Study of UHV Gas Captured by
Freshly Ion Etched Molybdenum
 
Reveals Chemical Shifts and Chemical States that Develop from Highly Reactive Pure Moo

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.
Initial spectra are at the front.  Final spectra are at the rear. Flood gun is OFF.
 
 
 
Mo (3d) Signal
 O (1s) Signal C (1s) Signal
     
 
 
Copyright ©:  The XPS Library
 

 

AES Study of UHV Gas Captured by
Freshly Ion Etched Molybdenum

Molybdenum sheet was ion etched and allowed to react with residual UHV gases overnight – ~14 hr run.

Mo (LMM) Signal:
Mo at front -> MoO X at rear 
Mo KE = 183.9 eV
O (KLL) Signal:
Mo at rear -> MoO X at front
O KE = 509.3eV
C (KLL) Signal:
Mo at front -> MoO X at rear 
O KE = 266.2 eV
 
     
   

 

Chemical State Spectra from Native Mo Oxide by AES
 

Mo (LMM) Signal:
Native Mo Oxide w charge control – Hemi-sphere (HSA) – 25 kV
High Energy Resolution Mode for Chemical States
O (KLL) Signal:
Native Mo Oxide – Hemi-sphere (HSA) – 25 kV
High Energy Resolution Mode for Chemical States
C (KLL) Signal:
Native Mo Oxide – Hemi-sphere (HSA) – 25 kV
High Energy Resolution Mode for Chemical States

Features Observed

  • xx
  • xx
  • xx

 Periodic Table 


 


High Energy Resolution AES of MoO3

   

 

 

AES High Energy Resolution Survey Spectrum of PbMoO4
with Charge Control

 


 

 

Molybdenum Alloys

   
XxCu XxCu
 Periodic Table   
XxCu XxCu

 

Copyright ©:  The XPS Library 

 



 

XPS Facts, Guidance & Information

 Periodic Table 

    Element   Molybdenum (Mo)
 
    Primary XPS peak used for Peak-fitting:   Mo (3d5/2)  
    Spin-Orbit (S-O) splitting for Primary Peak:   Spin-Orbit splitting for “d” orbital, ΔBE = 3.1eV
 
    Binding Energy (BE) of Primary XPS Signal:   227.9 eV
 
    Scofield Cross-Section (σ) Value:   Mo (3d5/2) = 5.62       Mo (3d3/2) = 3.88
 
    Conductivity:   Mo resistivity =  
Native Oxide suffers Differential Charing
 
    Range of Mo (3d5/2) Chemical State BEs:   227 – 232 eV range   (Moo to MMoO4)  
    Signals from other elements that overlap
Mo (3d5/2) Primary Peak:
  S (2s)  
    Bulk Plasmons:   ~xx eV above peak max for pure  
    Shake-up Peaks:   xx  
    Multiplet Splitting Peaks:   xx  

 

 

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

xx 

 

Copyright ©:  The XPS Library 

 Periodic Table 



 

Information Useful for Peak-fitting Mo (3d5/2)

  • FWHM (eV) of Mo (3d5/2) for Pure Moo ~0.57eV using 25 eV Pass Energy after ion etching:
  • FWHM (eV) of Mo (3d5/2) for MoO3 ~1.0 eV using 50 eV Pass Energy  (before ion etching)
  • Binding Energy (BE) of Primary Signal used for Measuring Chemical State Spectra:  228 eV for Mo (3d5/2) with +/- 0.2 uncertainty
  • List of XPS Peaks that can Overlap Peak-fit results for Mo (3d5/2):  S (2s)

 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 Oxide:  Pure element FWHM << 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 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 


 

Contaminants Specific to Molybdenum

  • Molybdenum develops a thick native oxide due to the reactive nature of clean Molybdenum .
  • The native oxide of Mo Ox is 4-9 nm thick.
  • Molybdenum thin films often have a low level of iron (Fe) in the bulk as a contaminant or to strengthen the thin film
  • Molybdenum 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 s that readily oxidize in the air.
  • High levels of carbonate appear on reactive 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 s.  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 Mo (3d) peak as well as Mo (3p).
  • 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 Molybdenum (Mo)

  • Conductivity:  Molybdenum 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:  Mo (3d5/2) at 227 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:  210 – 240 eV
  • Recommended Extended BE Range for Measuring Chemical State Spectrum:  200 – 250 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 appear after ion etching Mo and various reactive surfaces.  Carbides form due to the presence of 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
 

 
     
     
     
     
     
     
     
     
     
 
 
 
 

 

Chemical State Spectra from Literature
 
 
xxx
 



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