Sro

SrCO3

SrF2

SrSO4

SrTiO3

SrZrO3

SrB4O7

SrSi2

BiSrCaCuO

Basic

XPS Spectra
Strontium (Sr) 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.

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Strontium metal  (Sr^o)
Survey, Peak-fits, BEs, FWHMs, and Peak Labels

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→  Periodic Table	→ Six (6) BE Tables
Survey Spectrum from Sro Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag (3d5/2) FWHM = 1.3 eV
→  Periodic Table	→ Six (6) BE Tables
Sr (3d) Spectrum from Sro – Raw Fresh exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV	Sr (3d) Spectrum from Sro – Peak-Fit Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV
Sr (3d) Spectrum from Sro – Extended  Fresh exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV	Sr (3d) Spectrum from Sro – Expanded Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV

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→  Periodic Table	→ Six (6) BE Tables
Sr (3p) Spectrum from Sro – Raw Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV	Sr (3p) Spectrum from Sro – Peak-Fit Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV
→  Periodic Table	→ Six (6) BE Tables
Auger Signals from Sro – Raw Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV	Valence Band Signals from Sro – Raw Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV
	na

Overlays
→  Periodic Table	→ Six (6) BE Tables
Sr (3d) Spectra – Overlay of Sro and SrSO4 Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV	Sr (3d) Spectra – Overlay of Sro and SrF2 Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV
Chemical Shift:  +0.8 eV	Chemical Shift:  -0.4 eV
→  Periodic Table	→ Six (6) BE Tables
Valence Band Spectra – Overlay of SrSO4, and SrF2 Freshly exposed bulk, Flood gun is OFF, sample conductive, Ag FWHM = 0.75 eV	Sr (3d) Spectra – Overlay of Sro, SrSO4, and SrF2 Freshly exposed bulk, Flood gun is OFF, sample conductive, 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

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End-of-page

 

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Six (6) Chemical State Tables of Sr (3d_5/2) BEs

 

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

→  Periodic Table 

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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 

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Table #1

Sr (3d_5/2) 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
Sr	38	BiSrCaCuOx	132.2 eV		285.0 eV	The XPS Library
Sr	38	Sr-TiO3 (N*1)	132.7 eV		284.8 eV	Avg BE – NIST
Sr	38	SrTiO3	132.7 eV		285.0 eV	The XPS Library
Sr	38	Sr-(OH)2 (N*1)	133.0 eV		284.8 eV	Avg BE – NIST
Sr	38	Sr-CO3	132.9 eV		285.0 eV	The XPS Library
Sr	38	Sr-F2 (N*2)	133.7 eV	134.0 eV	284.8 eV	Avg BE – NIST
Sr	38	Sr-BO3	133.8 eV		285.0 eV	The XPS Library
Sr	38	Sr-F2	133.9 eV		285.0 eV	The XPS Library
Sr	38	Sr-SO4 (N*2)	134.0 eV	134.3 eV	284.8 eV	Avg BE – NIST
Sr	38	Sr(NO3)2 (N*1)	134.2 eV		284.8 eV	Avg BE – NIST
Sr	38	Sr – element	134.3 eV		285.0 eV	The XPS Library
Sr	38	Sr-SO4	134.9 eV		285.0 eV	The XPS Library
Sr	38	Sr-I2 (N*1)	135 eV		284.8 eV	Avg BE – NIST
Sr	38	Sr-O  (N*1)	135.3 eV		284.8 eV	Avg BE – NIST

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 (2p_3/2) BE = 932.62 eV and Au (3d_7/2) 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 

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Table #2

Sr (3d_5/2) Chemical State BEs from:  “PHI Handbook”

C (1s) BE = 284.8 eV

→  Periodic Table 

Copyright ©:  Ulvac-PHI

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Table #3

Sr (3d_5/2) Chemical State BEs from:  “Thermo-Scientific” Website

C (1s) BE = 284.8 eV

Chemical state	Binding energy (eV), Sr (3d5/2)
SrO	132.9
SrCO3	133.4
SrTiO3	133.1

→  Periodic Table 

Copyright ©:  Thermo Scientific 

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Table #4

Sr (3d_5/2) 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

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Table #5

Sr (3d_5/2) 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
Sr	3d5/2	SrRh2O4	133.0	±0.3	132.7	～	133.3
Sr	3d5/2	SrCO3	133.3	±0.2	133.1	～	133.5
Sr	3d5/2	SrMoO4	133.5	±0.2	133.3	～	133.7
Sr	3d5/2	SrF2	133.8	±0.3	133.5	～	134.0
Sr	3d5/2	SrSO4	134.4	±0.3	134.1	～	134.6
Sr	3d5/2	Sr	134.5	±0.3	134.2	～	134.7
Sr	3d5/2	Sr(NO3)2	134.8	±0.3	134.5	～	135.0
Sr	3d5/2	SrO	135.4	±0.3	135.1	～	135.6

→  Periodic Table 

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Histograms of NIST BEs for Sr (3d_5/2) BEs

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

Histogram indicates:  134.3 eV for Sro based on 2 literature BEs	Histogram indicates:  134.1  eV for SrO based on 2 literature BEs

Table #6

NIST Database of Sr (3d_5/2) 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.

 

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Statistical Analysis of Binding Energies in NIST XPS Database of BEs

 

 

 

→  Periodic Table