The microstructure information, i.e. average domain size and microstrain, may be different in thin films of distinct thicknesses, processing routes, etc. Thus, we could consider the line profile analysis applied to X-ray diffraction (XRD) patterns only as complementary to other characterization techniques, mostly electron microscopy.
Please give your opinion, with example. Thank you.
In general, I'd think SAXS & GIXRD are good options for characterizing the Nano structure of polycrystalline thin films depending on the material and morphology. In my vocabulary, SAXS, WAXS, GIXRD etc., all qualify for "line profile analyses" and would differ based on how the "line profile" (reciprocal space volume measurement) was acquired. 3D XRD reciprocal data contains all the nanostructural details. Interpretation and correct deconvolution are key!
1. What is the typical grain size & thickness in the films that you are discussing?
2. When you say "line profile analysis applied to X-ray diffraction (XRD) patterns", I must assume you mean a conventional linear equatorial powder diffractogram acquired with a 0D detector (Theta-2Theta scan). Correct?
Rather than using XRD "patterns only as complementary to other characterization techniques", I'd use XRD as the preliminary Nano structure characterization tool invariably. XRD is NDE and in situ compared with the tedious destructive "sample prep" in TEM. The challenge usually is interpretation, in XRD, due to the fact that the conventional methods present the convolution of instrument, grain size, strain and other Nanostructural features all in one profile with complete "spatial blindness". If at all one wishes to use the conventional diffractogram, then the WPPM (Scardi, Leoni et al) approach would probably provide the best results.
To more directly answer your question. Line profile analysis is not very effective for size or strain. The same goes for SEM or TEM.
In general, I'd think SAXS & GIXRD are good options for characterizing the Nano structure of polycrystalline thin films depending on the material and morphology. In my vocabulary, SAXS, WAXS, GIXRD etc., all qualify for "line profile analyses" and would differ based on how the "line profile" (reciprocal space volume measurement) was acquired. 3D XRD reciprocal data contains all the nanostructural details. Interpretation and correct deconvolution are key!
1. What is the typical grain size & thickness in the films that you are discussing?
2. When you say "line profile analysis applied to X-ray diffraction (XRD) patterns", I must assume you mean a conventional linear equatorial powder diffractogram acquired with a 0D detector (Theta-2Theta scan). Correct?
Rather than using XRD "patterns only as complementary to other characterization techniques", I'd use XRD as the preliminary Nano structure characterization tool invariably. XRD is NDE and in situ compared with the tedious destructive "sample prep" in TEM. The challenge usually is interpretation, in XRD, due to the fact that the conventional methods present the convolution of instrument, grain size, strain and other Nanostructural features all in one profile with complete "spatial blindness". If at all one wishes to use the conventional diffractogram, then the WPPM (Scardi, Leoni et al) approach would probably provide the best results.
I asked specifically "line profile analysis using XRD" because just recently I found this Whole Powder Pattern Modelling method applied mostly for nanocrystalline powders. However, This method allows to determine crystallite size and strain, thus, I thought why we could not use (with careful parameters selection) it for thin films (I mean 200-600nm thick coatings).
Do you know some examples (published works) with the WPPM (Scardi and Leoni) applied for thin films?
Thanks for your comments!
What substrate and what film materials?
SAXS for diffracting domain size estimate and XRR to give you film thickness estimate, would be my guess. If you have sufficient SNR for GIXRD then you may apply the WPPM principles, I suppose.
200-600 nm film should be amenable to most XRD techniques, in my opinion. I know from epitaxial films that even a 50 nm epi film can produce a topograph with significant SNR on a conventional XRD system
Substrate: Platinized Si.
Film: Alkali tantalates within perovskite oxide.
Film: Alkali tantalates within perovskite oxide: https://www.researchgate.net/publication/229131215_Structural_chemistry_of_new_ion-exchangeable_tantalates_with_layered_perovskite_structure_new_dionjacobson_phase_MCa2Ta3O10_(M__alkali_metal)_and_ruddlesdenpopper_phase_Na2Ca2Ta3O10
Substrate: Platinized Si: http://www.vinkarola.com/pdf/PlatinizedSiWafers.pdf
Article Structural chemistry of new ion-exchangeable tantalates with...
I've obtained very good results for thin copper films deposited on silicon substrates, from 100 to 600 nm of thickness. Below 100 nm the results are not so good. I've used the Mateo Leoni's software, PM2K. More information can be found in the PM2K manual.
Thanks Henry for your comments.
Pls tell me, did you use grazing incidence XRD?
You're welcome Sebastian,
I've used conventional theta-2theta scan. I've measured peak by peak maximizing the intensities. Then I input the normalized intensities in the PM2K software. Prior to this I've measured the LaB6 standard for the instrumental resolution determination, following the PM2K manual.
Good work! Please post both profiles when convenient Henry. At least the standard. It can't be proprietary :-)
I'd like to compare it with my limited 2D LaB6 data from BNL.
I need to reduce the noise in my scan...How i rectify that problem???
Let's not forget the use of XRR line profile analyses for layer Nano structure determination. See attached examples for the NIST 2000 (STANDARD REFERENCE MATERIAL) and a Pt. thin film sample on Si (001) substrate.
https://www.youtube.com/watch?v=cxPpKff3k5c
TEM cannot be used for similar analyses. Certainly not "in situ" as with XRD :-)
https://www.youtube.com/watch?v=cxPpKff3k5c
https://www.researchgate.net/post/Can_XRR_X-Ray_Reflectivity_be_implemented_in_the_Topographic_Mode_with_spatial_resolution_over_the_sample_surface_Is_there_value_for_such_analyses?_tpcectx=profile_questions
https://www.researchgate.net/post/Would_anyone_have_a_clue_as_to_the_origin_of_unexpected_spots_in_the_real_time_2D_XRR_signal_from_thin_film_samples_on_substrates_Yoneda_Spots?_tpcectx=profile_questions
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