Dear Rietvelders,
Does anyone know how FullProf calculates weight fractions “Fract(%)” in a .sum
file? or Is there any known bugs for calculating ATZ?
According to the manual, it seems that ATZ is used for calculating the
values... but no further information is written in the manual.
I am also wondering, in my case, why different phases have the exact same value
for ATZ. It should be different for different materials from the definition in
the manual.
Here are the related descriptions in my .out file.
Phase 1
=> The given value of ATZ is 688.48 the program has calculated:
4345.96
Phase 2
=> The given value of ATZ is 688.48 the program has calculated:
576.91
I confirmed that 4345.96 and 576.91 seem to be Z*Mw
I calculated the weight fractions using the values in the sum file and a
equation Wp=S_p(ZMV)_p/ΣS_i(ZMV)_i (R. J. Hill and C. J. Howard, J Appl.
Cryst., 20, 467-474), and ended up in getting quite different fractions from
those in the .sum file. I got 97.3% and 2.7% with my calculation and the values
in the .sum file are like this.
Phase 1
=> Bragg R-factor: 2.74 Vol: 941.374( 0.009) Fract(%):
82.46( 0.85)
=> Rf-factor= 1.81 ATZ: 688.475 Brindley: 1.0000
Phase 2
=> Bragg R-factor: 7.65 Vol: 137.093( 0.079) Fract(%):
17.54( 0.97)
=> Rf-factor= 5.35 ATZ: 688.475 Brindley: 1.0000
When I ran an example pcr for quantitative phase analysis in Examples
(si3n4r.pcr), I got ATZ and weight fractions below
Si3N4 alpha
=> The given value of ATZ is 560.00 the program has calculated:
561.14
Si3N4 beta
=> The given value of ATZ is 280.00 the program has calculated:
280.57
=> Phase: 1 Si3 N4 alpha
=> Bragg R-factor: 0.969 Vol: 292.623( 0.016) Fract(%): 92.88( 0.44)
=> Rf-factor= 0.600 ATZ: 560.000 Brindley: 1.0000
=> Phase: 2 Si3 N4 beta
=> Bragg R-factor: 2.26 Vol: 145.711( 0.027) Fract(%): 7.12( 0.09)
=> Rf-factor= 1.09 ATZ: 280.000 Brindley: 1.0000
and the these fractions are consistent with those derived from the equation
Wp=S_p(ZMV)_p/ΣS_i(ZMV)_i.
I would like to know which weight fractions I should trust for my case…
Best regards,
Kotaro
//================//================//
Kotaro SAITO
High Energy Accelerator Research Organization
Institute of Materials Structure Science
1-1 Oho, Tsukuba, Ibaraki, 305-0801, Japan
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