International XPS Instrument Registry –  IXIR

On-line IXIR Database

available 24 hours everyday

What is the On-line IXIR Database?

The IXIR database is a collection (a database) of “Screen-Captured” images of peak-fitted XPS spectra that were measured from high energy resolution spectra of  the Cu (2p3), Cu (3p), and Au (4f7) signals from a specific XPS instrument located somewhere in the world at a university, a company, a research institute, a government lab, or a contract analysis lab.

Each specific XPS instrument was manufactured by a commercial manufacturer (i.e.  SSI, HP, VG, PHI, Kratos, Shimadzu, Omicron, Scienta, Leybold, AEI, Thermo, Ulvac-PHI, Specs, …)  and has a unique SERIAL NUMBER (#), and a Model Number, or a Model Name.  The Serial Number (#) and the name of the manufacturer form a unique identifier that is used in the IXIR database.  Unique identifiers are essential for a database system.

The combination of “manufacturer’s name & instrument serial number (#)” allows everyone to track that specific (unique) XPS instrument even if is sold or given to a university for free or the cost of moving it.  That unique identifier will be directly connected to the trend (run) of the measured calibration BEs (eV) produced by that unique XPS instrument, and also the other Calibration BEs (eg C 1s) used with that unique XPS instrument.

 

How will IXIR help me to make more reliable Chemical State Assignments?

By knowing the Calibration BEs normally used with (or generated by) a specific (unique) XPS instrument, the trend (run) behavior of the measured calibration spectra (Cu, Au), and the measured calibration BEs produced by or used on that unique instrument, everyone will know how to adjust the BEs “Published in the Journals” by the scientists who operated, maintained, and calibrated that specific, unique XPS instrument.

This information allows you (me, everyone) to know how to correct or adjust their published BEs to match my Energy Scale, which, in turn, allows you (me, everyone) to improve our chemical state assignments.

 

How to participate in the IXIR system to improve
my Chemical State Assignments?

To participate and be accepted into this IXIR system, the instrument owner (person responsible) must complete the IXIR Registration Form for his/her XPS instrument and agree to submit “Screen-Captures” of calibration measurement spectra on a monthly basis.

 

What kind of “Screen-Captured” images must be produced
to participate in the IXIR system?

To be allowed to access and review the Measured Calibration BEs of all XPS instruments from around the world, each XPS instrument owner (person responsible) is required, on a monthly basis, to submit “screen-captured” images from peak-fitted spectra measured from the Cu (2p3), Cu (3p), and Au (4f7) signals. These Screen-Captured images will be added to the IXIR database. If the monthly submissions of Screen-captured images falls behind by more than 3 months, then that instrument will become non-active and access to the IXIR system will be turned OFF.

A total of six (6) screen-captured images must be submitted to the IXIR on a monthly basis.  Three (3) raw, unprocessed, high energy resolution spectra from each calibration signal: Cu (2p3), Cu (3p), and Au (4f7) must be submitted monthly. Three (3) screen-captured images from peak-fitted spectra from each calibration signal, Cu (2p3), Cu (3p), and Au (4f7), must also be submitted monthly. Each of the six (6) screen-captured images must include the actual Calendar Date shown at the bottom-right of the computer screen and, at the same time, the spectra from Cu (2p3), Cu (3p), and Au (4f7).

To continue to be a member of the IXIR, the instrument owner (person responsible) must submit a set of six (6) screen-captured images to the IXIR on a monthly basis.

Each of the screen-captured images must show the raw spectra or peak-fitted spectra, and each screen-captured image must include the actual Calendar Date shown at the bottom-right of the computer screen.

 

Why is the IXIR database important?

The fundamental intent of the IXIR system is to improve the reliability, and validity of all BEs published in all the hundreds of international journals that publish XPS results around the world.

In 2001, the ISO published a set of Calibration BEs for Cu (2p3), Cu (3p), and Au (4f7) signals which are reported to be the most accurate and reliable BEs to use to calibrate any XPS instrument in the world.  If every instrument in the world was adjusted to use the Calibration BEs, then, from that point in time, we would start to read XPS BEs and chemical state assignments that are based on those ISO Calibration BEs.

Unfortunately, this “adjustment” to use ISO Calibration BEs has not been widely implemented.

Why?  There are a variety of reasons that might include:

  • We have a very large internal database of chemical state assignments and BEs and have no need to convert all BEs over to a new set of calibration BEs
  • We do not have access to the internal electronics and can not adjust the spectrometer dispersion to match the ISO BEs
  • We know that the literature and, also therefore the NIST SDR 20 database, is filled with widely varying calibration BEs, so we never try to use the NIST database or publications
  • We have never read about the ISO Calibration BEs
  • The ISO document on Calibration BEs is expensive
  • etc…

The intent or purpose of the IXIR system is reveal the true BEs being used around the world so that everyone can take published BEs and adjust them to match my (your) needs for making “reliable” chemical state assignments. The end goal is to produce Reliable chemical state assignments that produce advance materials and improve products used around the world.  Everyone at The XPS Library thanks you very much for your time and for your kind participation in the IXIR system.

 

Donations

Donations from Registered Membership, helps us to provide, free of charge, access to individual data-sets of monochromatic XPS spectra, data processing software, PDF Handbooks of XPS Spectra, and more are used to develop, maintain, and expand the free, on-line, International Database of “Screen-Captured” BE Measurements known as:  The International XPS Instrument Registry (IXIR).

 

 

Registration Form for IXIR Memberships

Everyone should complete the “Registration” form (23 questions, and privacy policy) to become an IXIR Member.   We look forward to having you as a member of “IXIR”!

 

Only administrators can add new users.

 

INTERNATIONAL XPS INSTRUMENT REGISTRY, “IXIR”

 

Reasons to build this registry and database

 

Question: 
Why should we register our XPS instrument(s) and all other XPS instruments around the world into an on-line database of high energy resolution, calibration BEs from peak-fits of just-measured Cu (2p3), Cu (3p), and Au (4f7) spectra that includes all key instrument information and monthly screen-captures of calibration spectra?

Main Answer:   
     To improve our efforts to produce advanced materials and products around the world.

 

 

By improving the validity, reliability, and usefulness of thousands of XPS BEs and chemical state (species) assignments that are published in hundreds of advanced, international scientific journals by thousands of serious and hardworking scientists around our great world we will help ourselves, manufacturers, and be able to produce even more advanced materials.

Many thousands of XPS BEs and chemical state (species) assignments are produced by thousands of different XPS scientists around the world that are published in several hundred different scientific journals around the world. All scientists and engineers are very responsible and are working hard to make the world a better place through the application of XPS.

Unfortunately, the calibration BEs, calibration methods, and key instrument parameters published in the scientific literature are different for the several thousands of different XPS instruments being used to make chemical state assignments from peak-fitted spectra. More importantly, many calibration details and key instrument details seldom, if ever, published. Why does this happen? It happens because today too many manuscripts are submitted and there are not enough reviewers who can review many manuscripts. On top of that, many journal editors do not require the author to include all pertinent and necessary calibration information or key instrument variables that affect the information being published,

To make reliable and useful chemical state assignments to the peaks produced from the XPS peak-fits just measured on your in-house XPS instruments, you and each scientist or engineer needs access to reliable chemical state BEs.

The NIST SRD 20 database of XPS BEs is thought to be useful but, in reality, the BEs in the NIST database serve as a useful guide because the uncertainties in BEs ranges from +/-0.5 eV for conductors to +/-1.5 eV for insulators. The original publications, referenced in the NIST database, did not publish a full set of calibration BEs and methods used to maintain or document the energy scales of the many hundreds of different XPS instruments used to produce the BEs in the NIST database. The upper end of the BE scale (500-1486 eV) does not have a calibration BE in the NIST database.  For this reason, the error in the upper end of the BE scale can be as large as 0.6 eV for the Cu (2p3) BE which is today used to calibrate all XPS instruments.

To make reliable chemical state assignments to your in-house XPS peak-fits by using published BEs, you need to know the calibration BEs and methods that were used by the author of those BEs and chemical state assignments that you want to reference.  In this manner you can be sure that the chemical state assignments for your peak-fits are as correct and reliable as possible.

Because many journal publications do not normally include all the necessary calibration BEs and essential information needed so that you can adjust your BE calibrations to correlate with the published calibration BEs so that you can use the BEs of the chemical state assignments that you want to reference, we have built the International XPS Instrument Registry and on-line database. This on-line database will help all scientists and engineers to maximize the reliability and usefulness of the BEs published in scientific journals produced around the world.

This IXIR database helps each scientist around the world to better understand each XPS instrument, what calibration BEs, and what calibration methods are being used on each XPS instrument listed in the IXIR database.

What is the registry?

The International XPS Instrument Registry (IXIR) is a collection of information from registered members that includes calibration BEs, measured monthly, and key instrument parameters from each XPS instrument that are stored in an on-line IXIR database that is available 24 hours every day to all registered members around the world.

Answers to the questions listed below will be available in the database for everyone to see and use 24 hours per day. The instrument maker, model, and serial number serve as the unique name of the instrument because that information will never change.

The questionnaire (shown below) is the starting point for all XPS scientists and instrument owners around the world who want to start to improve the reliability and usefulness of published BEs and chemical state assignments worldwide.

 

XPS instrument registration questions

  • preferred C (1s) BE for adventitious hydrocarbon peak?
  • do you normally use this C (1s) BE to charge correct BEs from insulating materials?
  • do you use any other peaks to charge correct BEs from insulating materials?
  • calibration BEs used for Cu (2p3), (3p), Au (4f7)?
  • are you willing to submit screen captured images of the spectra used to check the calibration BEs?
  • instrument serial number?
  • instrument maker name?
  • instrument model number or model name?
  • instrument geometries?
  • who normally checks the calibration BEs?
  • how frequently are the calibration BEs checked?
  • accepted error (uncertainty) range for calibration BEs?
  • pass energy used to measure calibration BEs?
  • C (1s) BE for freshly peeled graphite or HOPG?
  • work function of the spectrometer?
  • what is the FWHM of the Ag (3d5) signal after ion etching and what pass energy is used?
  • what is the name of the university, government lab, or company, where XPS instrument is installed?
  • what is the name of the group who runs the instrument?
  • what is the e-mail of the owner of the instrument?
  • physical address of the XPS instrument?
  • what is the Si (2p) BE for silicone oil?
  • do you have more than one XPS instrument?
  • today’s date?
  • may we display instrument owner’s name on the IXIR database?
  • how many people operate the instrument?
  • who services the XPS when it has trouble?
  • what is the normal pressure when collecting data?

 

By answering these questions, we will improve the reliability, validity, and usefulness of the thousands of XPS BEs published in scientific journal and the chemical state assignments that are published in international scientific journals and databanks.

ON-LINE IXIR DATABASE

 

The IXIR On-Line Database is a combination of:

 

1.        answers to the ”XPS instrument registration questions” shown above, and

2.        three (3) screen-captured images of “Validation Spectra” that are submitted monthly to the IXIR database for each XPS instrument

 

     The IXIR database is a free, on-line database of instrument calibration BEs, instrument parameters, and measured validation spectra produced on each instrument around the world by XPS scientists. The IXIR database is available 24 hour every day and provides users with vital information about each XPS instrument registered in the IXIR system. The software used for the database is the FileMaker Pro database software that runs on both Macintosh and Windows operating systems

 

The (3) screen-captured images document the high energy resolution peak-fitted spectra that are called “validation spectra” that are used to record calibration BEs before the energy scales are adjusted to produce the expected calibration BEs.  These three images of peak-fitted spectra will be stored in an on-line database open to all registered members, journal editors, and publication reviewers around the world.

 

Screen-captures of validation spectra – examples

  • screen-Capture of the just-measured high energy resolution Cu (2p3) chemical state spectrum with its peak-fit, BE values, and on-screen date-time
  • screen-Capture of the just-measured high energy resolution Cu (3p) chemical state spectrum with its peak-fit, BE values, and on-screen date-time
  • screen-Capture of the just-measured high energy resolution Au (4f7) chemical state spectrum with its peak-fit, BE values, and on-screen date-time

 

How to build and maintain the on-line IXIR database?

To set up this system initially, The XPS Library will contact XPS instrument owners around the world and ask each instrument owner to provide answers to the XPS instrument registration questions (shown above).  To help with this task, the Journal of Surface Science Spectra will be searched to collect instrument geometry that belongs to specific instrument models. The serial number is a unique, key number that is useful to keep track of instrument that move from time to time because we need to keep track of the BEs that belong to that specific instrument.

The FileMaker Pro database software will be used as the on-line database system to keep track of all information and screen-captured images of the peak-fits of spectra used to check calibration BEs. This database is available at no cost to all registered members.  All useful BE information and geometry information for each instrument will be included in numerical form in the on-line database.

The measured validation spectra and reference BEs will allow all users to make necessary adjustments in published BEs to better understand and interpret their in-house research BEs, and to make more accurate and more reliable chemical state assignments to their in-house peak-fits.

To achieve this goal The XPS Library will request all international XPS instrument owners or the responsible scientists (engineers) around the world to answer the list of instrument questions and to collect screen-capture images (via Print Screen, Snag-It, Snippet, or other software) of the just-measured high energy resolution validation spectra from just ion-etched “calibration metals”. Each spectrum must include the time-date information that is provided at the bottom right corner of all computer monitors.

 

How does the IXIR system work?

The 3 screen-captures, mentioned above, must be sent to the E-mail:  bvcrist @ xpslibrary.com, until the on-line database system can accept 3 images directly uploaded by each XPS instrument owner or manager.

Each month or two The XPS Library will send a request to instrument owners to submit the latest screen-captures of the validation spectra used to check calibration BEs for each XPS instrument and to submit “peak-fitted validation spectra” for that month.  Because there can be unexpected delays to check calibrations BEs, the on-line IXIR database will list delayed submissions as “Delayed”.

These high energy resolution peak-fitted validation spectra are high energy resolution peak-fitted spectra that are used to “check” if instrument energy scale needs to be adjusted slightly to produce the desired perfect calibration BEs.  These validation spectra are measured from freshly ion-etched calibration metals, such as Copper (Cu) and Gold (Au) with the true “date-of-measurement” shown in the screen-capture.

Desired perfect calibration BEs are not measured BEs.  Calibration BEs are not BEs measured by peak-fitting validation spectra. Desired perfect calibration BEs are the calibration BEs recommended by ISO, ASTM, DIN, JIS, BSI, etc. The desired calibration BEs are “Perfect” BEs that each tool owner hopes that their instrument will maintain without having to adjust any voltages or circuit boards.

To make the IXIR system work correctly to help all the XPS instrument owners around the world, each XPS instrument owner must measure, record, and peak-fit high energy resolution spectra from the Cu (2p3), Cu (3p), and Au (4f7) signals once per month.  The peak-fitted results need to be screen-captured and submitted by e-mail to The XPS Library who will add the spectra and the measured validation BEs to your section of the database. Each screen-captured image must include the time-date stamp shown at the bottom right of the computer screen.

 

What is the goal / intention of the IXIR database?

The goal (purpose) of the IXIR database is to improve the reliability, validity, and usefulness of the thousands of BEs and chemical state (species) assignments published in hundreds of advanced, international scientific journals by those scientists who use the IXIR database.

The screen-captures and the instrument information stored in the IXIR database will help each of us to know how to modify (correct) thousands of published BEs to match our BE scale by knowing the calibration Cu (2p3), Cu (3p), Au (4f7) BEs that is used on XPS instrument used by other XPS scientists.

The IXIR database provides not only validation spectra, but also the user-defined C (1s) BE assigned to the adventitious hydrocarbons that is used to charge correct (charge reference) non-conductive insulators.  This C (1s) BE may not be the best reference energy for insulators, but, at this time, it is the most common BE used to charge reference (correct) insulators. This BE is currently given a BE that ranges from 284.2 to 285.2 eV with uncertainties of +/-0.2 eV.  Due to these variations, the IXIR needs to include the C (1s) BE of adventitious hydrocarbons in the database.

The goal of this on-line database is to provide all members of the XPS community, who use XPS spectra and data, with BEs and chemical state assignments that are as reliable, valid, and as accurate as possible.

 

How will the on-line IXIR database help me?

The desired (perfect) calibration BEs for each XPS instrument (based on serial number, #, maker name and model # or name) will be listed in the on-line IXIR database.  This on-line database will be available 24 hours per day to Registered Members around the world.  This on-line database of measured BEs from Cu (2p3), Cu (3p), and Au (4f7), together with the desired (or expected) calibration BEs, and Instrument Performance results will help everyone around the world by revealing BEs scales, the trends (run charts), and user-defined choices of the C (1s) BE (eV).

  • This IXIR On-Line Database system helps each scientist around the world to better understand how to correct published XPS BEs to match the calibrations used on in-house XPS instruments.
  • Improve the accuracy and correctness of the XPS results, BEs, and chemical state assignments that each XPS user publishes, and that we find in thousands of scientific journals,
  • Improve the reliability of the measured BEs from non-conductive insulators, and conductive materials published in domestic and international journals
  • Help each of us to measure more reliable chemical states, which will greatly advance the products produced by Material Science in our future
  • By knowing the exactC (1s) BE (eV) of the adventitious hydrocarbon that was used to charge reference (charge correct) BEs published in a publication each of us will be able to correct published BEs to match our preferred C (1s) BE (eV).
  • By knowing the exact Cu (2p3) BE (eV) that were used for a specific XPS instrument (based on serial #), we can adjust their published BEs to match the energy scale of our in-house XPS instrument and make more accurate chemical state assignments.
  • Old literature shows us that the measured BEs used to calibrate the low BE end of the energy scale do not vary a large amount, but the old maker reference literature shows us that the HIGH BE end of the energy scale suffered from a range of Cu (2p3) BEs that range from 932.2 eV to 932.8 eV.  This 0.6 eV uncertainty in the upper BE scale means that BEs in the 500-1400 eV range need to be “scaled” as the BE of the scale increases.  This represent a non-linear scaling problem that caused many high BE chemical state assignments to be misleading.
  • Research on the BEs of Cu (2p3) and Au (4f7) BEs obtained from a series of freshly ion etched AuCu alloys (75:25, 50:50, 25:70 ratios) shows that XPS can readily and reliably resolve small chemical state shifts, as small as 0.2 to 0.3 eV. This indicates that we have a chance to reliably measure such small chemical shifts in the future after the literature is full of more reliable BEs
  • The IXIR Database will help each of us how to know how to modify (correct) thousands of published BEs to match our in-house BE scale by knowing the calibration Cu (2p3), Cu (3p), Au (4f7) BEs that were used on any and all XPS instrument recorded in this database.
  • Build an On-Line Spectrabase system that will clearly show the reliability or unreliable nature of the thousands of the BEs produced from thousands of different materials by the thousands of different XPS instruments located around our world

 

How do I access the on-line IXIR database?

The web address for the on-line IXIR database will be shared with each registered member of The XPS Library. Each user can access the IXIR database 24 hours per day free of charge.

Is the IXIR database free?

Yes. The IXIR database is free to all registered members. We hope that the lab director of each XPS group around the world will make a small donation of $50 each year to help pay the costs of maintaining the database on the internet.

 

What information is needed from each XPS instrument tool owner for each XPS instrument?

  • name of instrument maker
  • name or model number of the XPS instrument
  • instrument serial number
  • calibration BEs currently being used for Cu (2p3), Cu (3p), and Au (4f7) peak maxima
  • user preferred C (1s) BE for adventitious hydrocarbon signal used to charge reference non-conducting samples
  • date that calibration BEs were last checked – must be visible in screen capture (NOTE: manually recorded BE values are not accepted, only screen-captures are accepted)
  • name (or email) of instrument owner
  • name (or email) of person responsible to maintain the XPS instrument

 

What information will be stored in the IXIR database?

  • user preferred C (1s) BE for adventitious hydrocarbon peak?
  • is that C (1s) BE always used to charge correct BEs from insulating materials?
  • what other peak is used to charge correct BEs from insulating materials?
  • calibration BEs used for Cu (2p3), (3p), Au (4f7)?
  • date of last check of calibration BEs?
  • will you submit screen captured images of the spectra used to check the calibration BEs?
  • instrument serial number?
  • instrument maker name?
  • instrument model number or model name?
  • instrument geometries?
  • who normally checks the calibration BEs?
  • how frequently are the calibration BEs checked?
  • accepted error (uncertainty) range for calibration BEs?
  • pass energy used to measure calibration BEs?
  • C (1s) BE for freshly peeled graphite or HOPG?
  • work function of the spectrometer?
  • what is the FWHM of the Ag (3d5) signal after ion etching and what pass energy is used?
  • what is the name of the university, government lab, or company, where XPS instrument is installed?
  • what is the name of the group who runs the instrument?
  • what is the e-mail of the owner of the instrument?
  • physical address of the XPS instrument?
  • what is the Si (2p) BE for silicone oil?
  • do you have more than one XPS instrument?
  • today’s date?
  • may we display instrument owner’s name on the IXIR database?
  • how many people operate the instrument?
  • who services the XPS when it has trouble?
  • what is the normal pressure when collecting data?

 

How do I join the IXIR system?

To join this system, each XPS instrument owner will need to provide a short list of instrument design variables as well as the name of the instrument maker, the model of the instrument, and most importantly the serial number of the instrument.  The serial number is needed because some XPS instruments are sold from one company to another, or from one university to another.

Who will maintain the IXIR database?

The XPS Library will maintain and pay for the website, the FileMaker Pro software, and maintenance for on-line access to the IXIR database.