Presently, I have been focused to study the crystallographic aspects of ~ 50 nm Gold thin film/ Si(001) substrate. As the thickness of the grown thin film is very small, during out of plane HRXRD measurements I am getting comparatively very small reflected intensity of Gold (in comparison with bulk Si(001)).
When going to below 10mrad (~0,5°) you will be in the angular regime of total reflection for your Au film. Here the penetration depth is only some atomic distances.
Dear Thomas Breuer,
Thank you very much for your valuable answer. I have gone through the above-mentioned two references. They are really very helpful.
With best regards,
Anjan
Dear Thomas Breuer,
Can you suggest how to determine critical angle for total internal reflection of the X-Ray ?
With best regards,
Anjan
Dear Anjan,
please have a look at my answer to a recent question, in which in the relation of the critical angle phic to the real part decrement delta of the x-ray refractive index is derived: phic = sqrt(2*delta)
https://www.researchgate.net/post/how_to_measure_the_critical_angle_in_XRRX-ray_reflectometery_result
The optical constant delta is given by:
delta = 415,2*10-6/(E[keV]²)* r[g/cm³]*Z/M[g]
with E the x-ray photon energy in keV, r = density of material in g/cm³, M= molecular/atomic mass and Z the atomic number. For molecules please add the atomic numbers according to the chemical formula.
I will send you the mentioned papers ( L.G. Parrat; Phys. Rev. Vol. 95, No. 2; pp. 359-369 (1954) and B. L. Henke; Phys. Rev. A, Vol. 6 No. 1; pp. 94 - 104 (1972) via RG messenger.
In addition you will find a formula there for estimation of penetration depth of x-rays in the total reflection regime.
Good luck and best regards
Dear Anjan Da,
You can estimate from the following online database.
http://henke.lbl.gov/optical_constants/atten2.html
I am attaching the sample picture with typical entries that needs to be used and then click on submit. You will get the output as shown in the attachment. I hope it will be useful for you in this regard.
Thanks and best regards,
Vantari Siva
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