Specifying Conductive Coatings for Standard and Unknowns

[John Donovan]

Then I think there might be a bug. How can I explain this?
So, I have an input file with two unknowns. I open that input file. Calczaf loads the first unknown. I set for the standards different coating thicknesses. I calculate. Then I press the load next dataset button. Now all my different thicknesses for the standards are lost.
Can you confirm this?

Hi Philipp,
There was a bug (Gian reported it a few months ago).  Update CalcZAF and all will be well.

Originally I was re-initializing the coating parameters for all standards each time a new unknown sample was loaded from the CalcZAF input file, and I shouldn't have been doing that. 

That said, if a subsequent sample in a single CalcZAF input file has one or more new standards (compared to prior samples in the input file), the program assumes the new standard(s) will utilize the last specified standard coating for subsequent unknown analyses.   So it's the user's responsibility to make sure the standard coatings (if they change for different standards during the CalcZAF file input process) are specified properly.   This is basically because the CalcZAF input format doesn't know anything about coatings...

In Probe for EPMA this is a non-issue because the coating parameters for each standard (and each unknown) are specified separately and retained for all subsequent calculations.  And of course all these standard or sample parameters can be modified as desired in subsequent calculations and are automatically saved... just curious why you are utilizing CalcZAF for sample calculations when you have Probe for EPMA?  Are you performing secondary fluorescence from boundary phase corrections in CalcZAF?
john

[Philipp Poeml]

Hi John,

I am updated and I still see this behaviour. Are you sure this is fixed?

Something similar is happening, when I open and export the whole file at once. I cannot have different coating thicknesses for the whole run, because they get reset to the same thickness for all standards.
My unknowns all use the same standards, nothing is changed (removed or added).
I use calczaf, because I have to experiment with the numbers and modifying the MDB is not so simple. Calczaf is nice for that. But it keeps resetting my coating thicknesses.

Cheers
Ph

[John Donovan]

Hi John,

I am updated and I still see this behaviour. Are you sure this is fixed?

Something similar is happening, when I open and export the whole file at once. I cannot have different coating thicknesses for the whole run, because they get reset to the same thickness for all standards.
My unknowns all use the same standards, nothing is changed (removed or added).
I use calczaf, because I have to experiment with the numbers and modifying the MDB is not so simple. Calczaf is nice for that. But it keeps resetting my coating thicknesses.

Cheers
Ph

Hi Philipp,
Don't you ever sleep?   Not sure if I like the sound of "I have to experiment with the numbers", but I'll let you be the judge of that!     

I'm pretty sure this bug was fixed a few months ago.   You're on v. 11.8.4?   Can you send me your CalcZAF input file (and Standard.mdb) by email?

I'll be around tomorrow if you can skype for a few minutes and we can go over the problem together.
john

[Philipp Poeml]

Hi John,

You are right it is (too) late here and I am on the way to sleep. But then, if I reply tomorrow, you are sleeping, and so we never come to a solution... Yes, 11.8.4. Sure, I can send you the file by email. And we can go over it. Thanks.

It is a long story why I do this. The short version is, I analyze Al in a sample, but sample and standards are coated with Al. And the thickness of the Al coating on standards and unknown is all different.

Cheers
Philipp

[John Donovan]

You are right it is (too) late here and I am on the way to sleep. But then, if I reply tomorrow, you are sleeping, and so we never come to a solution... Yes, 11.8.4. Sure, I can send you the file by email. And we can go over it. Thanks.

It is a long story why I do this. The short version is, I analyze Al in a sample, but sample and standards are coated with Al. And the thickness of the Al coating on standards and unknown is all different.

Hi Philipp,
Call me at 10 or 11 AM Pacific coast time (in about 18-19 hours).  I think we'll both be awake by then!

PFE should be able to handle different Al coating thicknesses for the standards and unknowns (I do it all the time), but send me the files and we can see what we see about CalcZAF.
john

[John Donovan]

It is a long story why I do this. The short version is, I analyze Al in a sample, but sample and standards are coated with Al. And the thickness of the Al coating on standards and unknown is all different.

Philipp and I discussed his situation and we now understand each other better. 

Basically he has samples (standards and unknowns) with different thicknesses of Al coating.  Unfortunately he needs to analyze for Al in his unknown samples!   Ugh!   

Probe for EPMA handles this situation of different coating thicknesses for standards and unknowns just fine (it even handles the situation of different standards with different coating materials and thicknesses), but because he is trying to measure the aluminum concentration in a sample which is coated with aluminum, he also wanted to find a way to "subtract" some of the Al Ka signal (that corresponds to the "excess" Al Ka signal from the Al coating, before the quantification of the Al in the actual sample!

So he thought that he might export the k-ratios from PFE and then edit the CalcZAF input file for this purpose.  The problem he ran into is that unlike Probe for EPMA, CalcZAF isn't quite as smart as PFE is about handling standards with different coatings... 

The problem that Gian ran into a few months ago was that CalcZAF was re-setting the coating parameters on the standards (back to 20 nm of carbon) when loading in a new unknown sample from the CalcZAF input file. This was fixed, but because each sample in a CalcZAF input file *could* have different standards, I re-load the standard parameters for the new sample which then resets the standard coating parameters back to the last coating specified for the previous standard.  This worked fine for Gian because his standards were coated differently than his unknowns, but all the standards were coated with the same thickness.

Not so for Philipp!  His standards (for some reason) are coated with different thicknesses of Al.  But then I realized that Philiip can simply do his aluminum intensity "tweaking" in Probe for EPMA by utilizing the "specified APF" parameter in the PFE Elements/Cations dialog to account for the "extra" Al signal from his coatings. This way he can utilize the extra power of PFE where one can specify each unknown and/or standard with different coating parameters and all is good.

Whew!

He will still need to be careful about fluorescence of the Al coating from his standard and unknown materials, but at least it is possible in PFE to specify different coating materials and thicknesses for each standard or unknown.
john

[Philipp Poeml]

Hi John,

Yes that summarises it pretty much I guess. I guess there is only Karen out there who understands my situation. She had the privilege of working together with me on these samples. 
We can give you more details on this analysis in Konstanz I guess.

Cheers
Philipp

[John Donovan]

To make things a little more clear I added additional output for CalcZAF which confirms the standard coating parameters (in addition to the already output unknown coating parameters) in the log window.  First thing (after opening your input file) is to remember to turn on the coating correction flags in the CalcZAF Analytical menu as seen here:



Here is the normal output for an unknown sample (2nd sample in the default input file CalcZAF.dat):

Fe2SiO4 from Intensities

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Standard 895, Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Standard 14, Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms

STANDARD PARAMETERS (TOA= 40):

 ELEMENT  STDNUM STDCONC STDKFAC   Z-BAR  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR COATTRNS COATABSR
   Fe Ka     895  72.080   .6781 20.9954   .9969  1.0000  1.0662  1.0629  .99994  .98001
   Si Ka      14  46.740   .4101 10.8047  1.1059  1.0000  1.0306  1.1397  .99703  .98427
    O Ka     895  27.640   .1948 20.9954  1.6505   .9937   .8650  1.4188  .92223  .98449

 ELEMENT STP-POW BKS-COR   F(x)e   F(x)s      Eo      Ec   Eo/Ec
   Fe Ka  1.0939   .9747   .9846   .9877   14.99  7.1120  2.1083
   Si Ka  1.0565   .9755   .9056   .8189   14.99  1.8390  8.1533
    O Ka   .7992  1.0823   .7008   .4246   14.99   .5317 28.1999

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms

SAMPLE: 2, TOA: 40, ITERATIONS: 4, Z-BAR: 18.68271

 ELEMENT  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR STP-POW BKS-COR   F(x)u      Ec   Eo/Ec    MACs uZAF/sZAF
   Fe ka   .9979  1.0000  1.0977  1.0954  1.1370   .9655   .9867  7.1120  2.1091 60.8022  1.030541
   Si ka  1.4033   .9993   .9549  1.3392   .9279  1.0292   .6453  1.8390  8.1566 1635.92  1.174991
   O  ka  1.8082   .9955   .8887  1.5998   .8337  1.0660   .3876   .5317 28.2114 3698.75  1.127603

 ELEMENT   K-RAW K-VALUE ELEMWT% OXIDWT% ATOMIC% FORMULA KILOVOL COATTRN COATU/S KILOVOL COATABS COATU/S
   Fe ka  .73722  .49993  54.762   -----  28.516   5.322   15.00  .99994  .99994   14.99  .98001  .98001
   Si ka  .25234  .10348  13.859   -----  14.349   2.678   15.00  .99703  .99703   14.99  .98427  .98427
   O  ka 1.00861  .19649  31.435   -----  57.135  10.663   15.00  .92223  .92223   14.99  .98449  .98449
   TOTAL:                100.056   ----- 100.000  18.663


However, since the coating is specified as the same for both the standards (#14 and #895) and the unknown, the calculation isn't significantly affected (though it might be if these elements were acquired at a very low overvoltage)...

Now we specify the unknown as having a say, 5 nm Al coating using the Calculation Options button in the CalcZAF program:

Fe2SiO4 from Intensities

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Standard 895, Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Standard 14, Coating=C, Density=2.1 gm/cm3, Thickness=200 angstroms, Sin(Thickness)=311.145 angstroms

STANDARD PARAMETERS (TOA= 40):

 ELEMENT  STDNUM STDCONC STDKFAC   Z-BAR  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR COATTRNS COATABSR
   Fe Ka     895  72.080   .6781 20.9954   .9969  1.0000  1.0662  1.0629  .99994  .98001
   Si Ka      14  46.740   .4101 10.8047  1.1059  1.0000  1.0306  1.1397  .99703  .98427
    O Ka     895  27.640   .1948 20.9954  1.6505   .9937   .8650  1.4188  .92223  .98449

 ELEMENT STP-POW BKS-COR   F(x)e   F(x)s      Eo      Ec   Eo/Ec
   Fe Ka  1.0939   .9747   .9846   .9877   14.99  7.1120  2.1083
   Si Ka  1.0565   .9755   .9056   .8189   14.99  1.8390  8.1533
    O Ka   .7992  1.0823   .7008   .4246   14.99   .5317 28.1999

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=Al, Density=2.7 gm/cm3, Thickness=50 angstroms, Sin(Thickness)=311.145 angstroms

SAMPLE: 2, TOA: 40, ITERATIONS: 4, Z-BAR: 18.85708

 ELEMENT  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR STP-POW BKS-COR   F(x)u      Ec   Eo/Ec    MACs uZAF/sZAF
   Fe ka   .9980  1.0000  1.0953  1.0932  1.1337   .9662   .9865  7.1120  2.1091 59.6358  1.028473
   Si ka  1.4062   .9993   .9533  1.3397   .9250  1.0307   .6440  1.8390  8.1566 1594.08  1.175423
   O  ka  1.8257   .9954   .8869  1.6118   .8310  1.0673   .3838   .5317 28.2114 3631.83  1.136095

 ELEMENT   K-RAW K-VALUE ELEMWT% OXIDWT% ATOMIC% FORMULA KILOVOL COATTRN COATU/S KILOVOL COATABS COATU/S
   Fe ka  .72726  .49317  53.913   -----  29.365   5.306   15.00  .99981  .99981   15.00  .99358  .99358
   Si ka  .25058  .10276  13.767   -----  14.910   2.694   15.00  .99327  .99327   15.00  .99494  .99494
   O  ka  .93342  .18185  29.311   -----  55.725  10.069   15.00  .98597  .98597   15.00  .99501  .99501
   TOTAL:                 96.991   ----- 100.000  18.069


Note the effect on the composition since Al absorbs these x-rays differently than carbon (note this isn't a real test as the unknown sample *was not* actually measured with a 20 nm Al coating, so the direction of the coating effect is in the wrong direction).  If I specify the same Al coating for the standards as well using the Standard | Edit Standard Parameters (coating) menu, we essentially get back our original composition:

Fe2SiO4 from Intensities

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Standard 895, Coating=Al, Density=2.7 gm/cm3, Thickness=50 angstroms, Sin(Thickness)=77.78624 angstroms

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Standard 14, Coating=Al, Density=2.7 gm/cm3, Thickness=50 angstroms, Sin(Thickness)=77.78624 angstroms

STANDARD PARAMETERS (TOA= 40):

 ELEMENT  STDNUM STDCONC STDKFAC   Z-BAR  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR COATTRNS COATABSR
   Fe Ka     895  72.080   .6781 20.9954   .9969  1.0000  1.0662  1.0629  .99981  .99358
   Si Ka      14  46.740   .4101 10.8047  1.1059  1.0000  1.0306  1.1397  .99327  .99494
    O Ka     895  27.640   .1948 20.9954  1.6505   .9937   .8650  1.4188  .98597  .99501

 ELEMENT STP-POW BKS-COR   F(x)e   F(x)s      Eo      Ec   Eo/Ec
   Fe Ka  1.0939   .9747   .9846   .9877   15.00  7.1120  2.1089
   Si Ka  1.0565   .9755   .9056   .8189   15.00  1.8390  8.1557
    O Ka   .7992  1.0823   .7008   .4246   15.00   .5317 28.2081

Using Conductive Coating Correction For Electron Absorption and X-Ray Transmission:
Sample Coating=Al, Density=2.7 gm/cm3, Thickness=50 angstroms, Sin(Thickness)=311.145 angstroms

SAMPLE: 2, TOA: 40, ITERATIONS: 4, Z-BAR: 18.68271

 ELEMENT  ABSCOR  FLUCOR  ZEDCOR  ZAFCOR STP-POW BKS-COR   F(x)u      Ec   Eo/Ec    MACs uZAF/sZAF
   Fe ka   .9979  1.0000  1.0977  1.0954  1.1370   .9655   .9867  7.1120  2.1091 60.8022  1.030541
   Si ka  1.4033   .9993   .9549  1.3392   .9279  1.0292   .6453  1.8390  8.1566 1635.92  1.174991
   O  ka  1.8082   .9955   .8887  1.5998   .8337  1.0660   .3876   .5317 28.2114 3698.75  1.127603

 ELEMENT   K-RAW K-VALUE ELEMWT% OXIDWT% ATOMIC% FORMULA KILOVOL COATTRN COATU/S KILOVOL COATABS COATU/S
   Fe ka  .73722  .49993  54.762   -----  28.516   5.322   15.00  .99981  .99981   15.00  .99358  .99358
   Si ka  .25234  .10348  13.859   -----  14.349   2.678   15.00  .99327  .99327   15.00  .99494  .99494
   O  ka 1.00861  .19649  31.435   -----  57.135  10.663   15.00  .98597  .98597   15.00  .99501  .99501
   TOTAL:                100.056   ----- 100.000  18.663


john