Tao Ta2O5 TaS2 TaSix TaC TaN TaF5 LiTaO4 Basic 

XPS Spectra
Tantalum (Ta) Compounds
The XPS Spectra section provides raw and processed survey spectra, chemical state spectra, BE values, FWHM values, and overlays of key spectra.
Atom% values from surveys are based on sample, as received, and Scofield cross-sections. Atom% values are corrected for IMFP and PE.
Peak-fits are guides for practical, real-world applications. Peak-fits are not fully optimized or designed to test any theory.

Tantalum Carbide  (TaC)
Survey, Peak-fits, BEs, FWHMs, and Peak Labels

→  Periodic Table   → Six (6) BE Tables
Survey Spectrum from TaC
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag (3d5/2) FWHM = 1.3 eV
→  Periodic Table  → Six (6) BE Tables
Ta (4f) Spectrum from TaC – Raw
Fresh exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV		 Ta (4f) Spectrum from TaC – Peak-Fit
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV

 
Ta (4f) Spectrum from TaC– Extended Range
Fresh exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV		 Ta (4f) Spectrum from TaC – Raw – Vertically Expanded
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV
→  Periodic Table  → Six (6) BE Tables
O (1s) Spectrum from TaC – Raw
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV		 O (1s) Spectrum from TaC – Peak-Fit
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV
→  Periodic Table  → Six (6) BE Tables
C (1s) Spectrum from TaC – Raw
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV		 C (1s) Spectrum from TaC – Peak-Fit
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV
→  Periodic Table  → Six (6) BE Tables
C (KLL) Auger Signals from TaC – Raw
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV		 Valence Band Signals from TaC – Raw
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV
na
 
Overlays
→  Periodic Table  → Six (6) BE Tables
Valence Band Spectra – Overlay of Tao and TaC
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV		 Ta (4f) Spectra – Overlay of Tao and TaC
Freshly exposed bulk, Flood gun is OFF (conductive), C (1s) BE = 284.56 eV, Ag FWHM = 0.75 eV

End-of-spectra

Price to purchase raw data sets:
Raw spectra – VAMAS ASCII format ($6)
Raw spectra – SDP binary format ($5)
SDP v9 – $145 (3 yr license)

 

 

Transmission Function Tests
 

December 2015 – Transmission Function of Thermo K-Alpha Plus
→  Periodic Table 
Survey Spectra of Ion Etched Copper (Sc), PEs = 50, 100, 150 and 200 eV
→  Periodic Table 
March 2016 – Transmission Function of Thermo K-Alpha Plus 
 
Survey Spectra of Ion Etched Copper (Sc), PEs = 100, 150 and 200 eV
→  Periodic Table  
August 2019 – Transmission Function of Thermo K-Alpha Plus
 
Survey Spectra of HOPG (C), PEs = 20, 50, 100 and 200 eV
→  Periodic Table  
January 2022 – Transmission Function of Thermo K-Alpha Plus
Survey Spectra of Ion Etched Copper (Sc), PEs = 100, 120, 140, 160, 180 and 200 eV

End-of-Transmission-Function-Tests

 

Six (6) Chemical State Tables of Hf (4f7/2) 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 (2p3/2) 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

Hf (4f7/2) 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
Hf 72 Hf (N*5) 14.2 eV 14.4 eV 284.8 eV Avg BE – NIST
Hf 72 Hf – element 14.2 eV 284.8 eV The XPS Library
Hf 72 Hf-C 14.4 eV 14.6 eV 285.0 eV The XPS Library
Hf 72 Hf-N (N*10) 14.7 eV 284.8 eV Avg BE – NIST
Hf 72 Hf-Si2 14.8 eV 285.0 eV The XPS Library
Hf 72 Hf-O2 (N*3) 16.7 ev 18.1 eV 284.8 eV Avg BE – NIST
Hf 72 Hf-O2 17.2 eV 285.0 eV The XPS Library
Hf 72 HfSiO4 17.4 eV 285.0 eV The XPS Library
Hf 72 Hf(SO4)2 19.3 eV 285.0 eV The XPS Library
Hf 72 Hf-F4 20.0 eV 285.0 eV The XPS Library
Hf 72 Hf-S2 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 (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

Hf (4f7/2) Chemical State BEs from:  “PHI Handbook”

C (1s) BE = 284.8 eV

→  Periodic Table 

Copyright ©:  Ulvac-PHI

Table #3

Hf (4f7/2) Chemical State BEs from:  “Thermo-Scientific” Website

C (1s) BE = 284.8 eV

Chemical state Binding energy (eV), Hf (4f7/2)
Hf metal 14.3
HfO2 18.3

→  Periodic Table 

Copyright ©:  Thermo Scientific 

Table #4

Hf (4f7/2) 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

Hf (4f7/2) 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
Hf 4f7/2 Hf 14.3 ±0.2 14.1 ～ 14.5
Hf 4f7/2 HfO2 16.7 ±0.3 16.4 ～ 17.0
Hf 4d5/2 Hf 212.3 ±0.3 212.0 ～ 212.5
Hf 4d5/2 HfO2 213.3 ±0.3 213.0 ～ 213.6

 

→  Periodic Table 

 

Histograms of NIST BEs for Hf (4f7/2) BEs

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

 

Histogram indicates:  14.3 eV for Hfo based on 5 literature BEs

Table #6


NIST Database of Hf (4f7/2) 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 Species Chemical BE (eV) Reference
Hf 4f7/2 Hf 14.23 Click
Hf 4f7/2 Hf 14.28 Click
Hf 4f7/2 Hf 14.30 Click
Hf 4f7/2 Hf 14.31 Click
Hf 4f7/2 Hf 14.35 Click
Hf 4f7/2 Hf 14.40 Click

 

 

Statistical Analysis of Binding Energies in NIST XPS Database of BEs

 

 

→  Periodic Table 

 

→  Periodic Table