Sorry I'm going to be picky here - its labelled ZAF, phi(pz), but none of them are ZAF, are they not all phi-rho-z?
Ben
Quote from: Ben Buse on February 05, 2019, 05:36:27 AM
Sorry I'm going to be picky here - its labelled ZAF, phi(pz), but none of them are ZAF, are they not all phi-rho-z?
Ben
Hi Ben,
Note that it says ZAF *comma* Phi (pz) *and* characteristic fluorescence corrections.
It's just saying there are several ZAF correction methods, several phi-rho-z correction methods and also the fluorescence correction options.
(https://smf.probesoftware.com/gallery/395_05_02_19_8_22_11.png)
What would you prefer it to say?
Thanks John,
Thats helpful, I did not spot some of them use ZAF method for absorption corrections (as oppose to integrating depth slices of phi(rz) curve).
I don't know what I'd prefer to say, I guess the key distinction is between phi rho z, phi rho z and ZAF combo's and true ZAF (such as offered as standard by JEOL)
(Its actually phi(rz), A & F selections - but that would be difficult to understand!). "Matrix corrections"?
Ben
Quote from: Ben Buse on February 05, 2019, 08:39:24 AM
Thanks John,
Thats helpful, I did not spot some of them use ZAF method for absorption corrections (as oppose to integrating depth slices of phi(rz) curve).
I don't know what I'd prefer to say, I guess the key distinction is between phi rho z, phi rho z and ZAF combo's and true ZAF (such as offered as standard by JEOL)
(Its actually phi(rz), A & F selections - but that would be difficult to understand!). "Matrix corrections"?
Ben
Hi Ben,
What the heck is a "true ZAF"? All of these ZAF methods are "true ZAFs" as far as I know! Sounds like a "no true Scotsman" to me! ;)
https://en.wikipedia.org/wiki/No_true_Scotsman
The only problem with labeling the dialog as "Matrix Corrections" is that these are only a portion of the matrix corrections offered in CalcZAF/Probe for EPMA/CalcImage as seen in the dialog just prior to the one we're talking about:
(https://smf.probesoftware.com/gallery/395_05_02_19_9_46_33.png)
I would ague that alpha factor methods based on the analytical corrections or the fast Monte Carlo binaries from Penepma k-ratios or the multi-standard calibration curves are all "matrix corrections" of one kind or another.
Sorry if I'm missing something...
Your right!
But there is a distinguish between phi-rho-z (exponential function to experimental measurements), and the original ZAF equations, we know the phi-rho-z models perform significantly better.
https://smf.probesoftware.com/index.php?topic=890.msg5683#msg5683 (https://smf.probesoftware.com/index.php?topic=890.msg5683#msg5683)
The trouble is it gets confusing as phi-rho-z is converted into Z and A factors for application. I guess some things are difficult to simplify for teaching, etc.
I regret the original question (should think before posting!), I don't think the name is the problem, but how to convey the essential information.
Things like the difference between the phi rho z models (gaussian, parabolic fit etc) or their performance on PAP dataset.
(https://smf.probesoftware.com/gallery/453_05_02_19_10_51_51.png)
Jacky Ruste (GN-MEBA)
http://micro.icaunais.free.fr (http://micro.icaunais.free.fr)
I certainly agree that ZAF and phi-rho-z methods are different! ;D
In fact the only reason for including the traditional ZAF methods in CalcZAF and Probe for EPMA is for historical comparisons. We can get the same (original) results with the Shaw data set from the 1970's using these ZAF methods! By the way, I think the Shaw dataset is included with the CalcZAF installer. Here is an email discussion with Paul Carpenter on this that I posted here with his permission some time ago:
https://smf.probesoftware.com/index.php?topic=924.msg5944#msg5944
As you said, my preferred explanation to the students is to say that phi-rho-z methods combine the Z and A effects, and for that I utilize some graphs. Some of my, now quite ancient PPT slides and lecture notes, are found here:
https://epmalab.uoregon.edu/lecture.htm
The matrix correction lecture is here:
https://epmalab.uoregon.edu/pdfs/Electron%20Beam%20MicroAnalysis-Geol_619-12.ppt
john
Here's another technique I use with students. Calculate compositions for measurements using *all* the different matrix corrections. Here's an example using one of the NIST Au-Cu (20/80) standards:
Summary of All Calculated (averaged) Matrix Corrections:
AUCU_NBS-K-RATIOS.DAT, Sample 1
LINEMU Henke (LBL, 1985) < 10KeV / CITZMU > 10KeV
Elemental Weight Percents:
ELEM: Cu Au TOTAL
1 20.079 80.283 100.362 Armstrong/Love Scott (default)
2 19.473 81.423 100.895 Conventional Philibert/Duncumb-Reed
3 20.358 80.265 100.624 Heinrich/Duncumb-Reed
4 19.820 80.247 100.066 Love-Scott I
5 19.908 80.380 100.288 Love-Scott II
6 18.772 80.589 99.361 Packwood Phi(pz) (EPQ-91)
7 21.323 79.946 101.269 Bastin (original) Phi(pz)
8 19.589 80.142 99.731 Bastin PROZA Phi(pz) (EPQ-91)
9 19.607 80.119 99.726 Pouchou and Pichoir-Full (PAP)
10 19.738 80.136 99.874 Pouchou and Pichoir-Simplified (XPP)
AVER: 19.867 80.353 100.220
SDEV: .661 .413 .588
SERR: .209 .131
MIN: 18.772 79.946 99.361
MAX: 21.323 81.423 101.269
This is output from CalcZAF, but one can also do it from Probe for EPMA on their own measurements. Then ask the students: which one is "correct"? :)
Of course the classic example is the SiIr alloy from Armstrong that Paul Carpenter worked on:
Summary of All Calculated (averaged) Matrix Corrections:
#1 approx. Ir45Si55 (atomic) based on Ir3Si5 standard
LINEMU Henke (LBL, 1985) < 10KeV / CITZMU > 10KeV
Elemental Weight Percents:
ELEM: Ir Si TOTAL
1 84.502 14.308 98.810 Armstrong/Love Scott (default)
2 86.715 11.781 98.496 Conventional Philibert/Duncumb-Reed
3 84.863 12.910 97.773 Heinrich/Duncumb-Reed
4 84.339 12.819 97.158 Love-Scott I
5 84.329 12.833 97.162 Love-Scott II
6 84.208 11.075 95.283 Packwood Phi(pz) (EPQ-91)
7 86.129 13.997 100.126 Bastin (original) Phi(pz)
8 84.658 12.708 97.366 Bastin PROZA Phi(pz) (EPQ-91)
9 84.531 12.836 97.367 Pouchou and Pichoir-Full (PAP)
10 84.295 12.633 96.929 Pouchou and Pichoir-Simplified (XPP)
AVER: 84.857 12.790 97.647
SDEV: .858 .929 1.290
SERR: .271 .294
MIN: 84.208 11.075 95.283
MAX: 86.715 14.308 100.126
Atomic Percents:
ELEM: Ir Si TOTAL
1 46.325 53.675 100.000 Armstrong/Love Scott (default)
2 51.820 48.180 100.000 Conventional Philibert/Duncumb-Reed
3 48.995 51.005 100.000 Heinrich/Duncumb-Reed
4 49.016 50.984 100.000 Love-Scott I
5 48.986 51.014 100.000 Love-Scott II
6 52.630 47.370 100.000 Packwood Phi(pz) (EPQ-91)
7 47.347 52.653 100.000 Bastin (original) Phi(pz)
8 49.328 50.672 100.000 Bastin PROZA Phi(pz) (EPQ-91)
9 49.040 50.960 100.000 Pouchou and Pichoir-Full (PAP)
10 49.368 50.632 100.000 Pouchou and Pichoir-Simplified (XPP)
AVER: 49.285 50.715 100.000
SDEV: 1.839 1.839 .000
SERR: .582 .582
MIN: 46.325 47.370 100.000
MAX: 52.630 53.675 100.000
The customer's question was is it the 50:50 atomic phase or the 45:55 atomic phase?