Both compounds are cubic with almost equal lattice parameters and the same set of the systematic absences, so the positions of the peaks should be almost the same. But the structure is completely different: FeN has a sphalerite structure (F -4 3 m) and FeO has a rock-salt structure (F m -3 m). As a result, the relative intensities of the peaks should be completely different. It can be not very easy to observe in case of the highly oriented thin films, but careful analysis of your diffraction data should lead to the unambiguous conclusion.

Both compounds are cubic with almost equal lattice parameters and the same set of the systematic absences, so the positions of the peaks should be almost the same. But the structure is completely different: FeN has a sphalerite structure (F -4 3 m) and FeO has a rock-salt structure (F m -3 m). As a result, the relative intensities of the peaks should be completely different. It can be not very easy to observe in case of the highly oriented thin films, but careful analysis of your diffraction data should lead to the unambiguous conclusion.

thank you, what additional technique you can suggest me to use in order to differentiate them? 

Perhaps, Mössbauer spectroscopy or neutron diffraction will be able to help you

Mössbauer spectroscopy is just applicable to iron-containing phases and is good for detecting nearest-neighbor cation environment. But in the case of the small amount of samples, it is recommended for signal amplification to add the isotope Fe57 during the process of sample preparation. Neutron diffraction is applicable for identifying both the atomic and magnetic structure. It is the only direct method which gives full information about the magnetic moments of the atoms and the dimensional characteristics in the unit cell of the crystal structure.

Please post your diffractograms for best feedback from the expert RG network :-)

https://www.flickr.com/photos/85210325@N04/11487549683/in/album-72157645018820696/

@ravi Thank you, I attached the file.

Stefan! Please do include the data set in the original question itself by editing. That will make it easy for review.

Now how about describing the details of the measurements?

BTW I notice you have several unidentified "peaks". What's up?

• Is the substrate polycrystalline? Appears so from the diffractogram.
• What do you expect for the film Nano structure? Preferred orientation? Amorphous or low crystallinity component?

https://www.flickr.com/photos/85210325@N04/10221065324/in/album-72157645018820696/

https://www.flickr.com/photos/85210325@N04/29413288423/in/dateposted/

the part that you see ( in circuled question mark) is quarz substrate.

I used grazing incidence XRD with angle only 1 degree.

I expect polycrystalline. since that what SAED suggested, with XRD I hope that I can see more about composition.

start-stop angle 5-80 deg , step size 0.02 deg and speed 3 deg/min.

there is also minor phase, I cannot detect it and comprehend it yet which one is it.

Stefan, your scan time is too fast. The data are poor because of this. Only 25 counts at the maximum peak and background at around 5 counts is a poor signal/noise. Slow it right down. Take it at 0.5 deg/min, spend the time and gather really good data and you will struggle less. This should help you with the minor phases. Once you have gathered good data please post it, so others can analyse it and maybe suggest what you have.

The amorphous hump at 20 that Ravi circled looks more like glass substrate than quartz?? 

"I expect polycrystalline. since that what SAED suggested, with XRD I hope that I can see more about composition."

Please post any other data for the benefit of review like SAED, when available.

Film thickness and flatness? Film adhesion?

What do you think is the penetration depth of your X-ray beam into your sample?

Micrographs of the sample would help as well!

Just remember that the entire reciprocal space is visible during your XRD measurement. You have chosen to use the conventional linear diffractogram along the equatorial plane as do most others in the field of XRD. This conventional 0D method does not take full advantage of the omnipresent 2D data emanating from a 2D incident beam on a 2D sampling area on the specimen surface.

As Ian suggests, improve the resolution of your XRD data by using a slower scan rate and/or step size.

Is photographic film available or extinct in your lab? Since you don't seem to have a 2D detector :-) Just one exposure would open up a whole new window into your sample's Nano structure!

https://www.flickr.com/photos/85210325@N04/11343736043/in/album-72157645018820696/

https://www.flickr.com/photos/85210325@N04/10221987094/in/album-72157645018820696/

Corroborating with Dr. Alexander T. Morchenko , pls look in the following article ( Abstract given) to find discussion on their MS .

REF:

Hyperfine Interactions

April 1992, Volume 69, Issue 1, pp 455–458

Abstract:

Two new phases of FeNx films for x>0.5 have been identified: One has a ZnS-type structure denoted by γ" Another phase is denoted by γ''' in which iron atoms constitute a fcc lattice but the details of occupation sites of nitrogen atoms are not yet clear. The isomer shift of γ" relative to α-Fe at 300 K is rather small in comparison with that of other well known nitrides. The room temperature Mössbauer spectra of γ''' consist of a sum of two doublets. Mössbauer spectra of γ" at 10 K do not indicate magnetically split pattern, but those of γ''' show magnetically split patterns at 10 K with the hyperfine fields of 30 T and 48 T, respectively. The component of 48 T is due to oxides, not due to nitrides.

I attached SAED pictures,

I order from chemical company Quartz substrate, do you think I dont really have it? 

film thickness is between 100 and 500 nm, adhesion is normal. not loosely bond,  very strong adhesion, I will ask in monday technician about penetration and 2D detector

i assume it is deep penetration, because of Fe phase, I didn't anneal film and I assume lowwer levels, layers, are pure zerovalent iron.

Stefan, regarding the substrate - that is quite a strong signal coming from an amorphous (to X-ray) phase. Quartz is highly crystalline - unless they have given you something like cryptocrystalline silica. Have you tried Si low background plates? these should give a flat background without peaks. However, I think this is just a side-show.

If you are using Cu target, then fluorescence signal from Fe will be significant as well.

Got the diffractogram of the substrate without the film yet?

Rotate the sample surface about its normal and repeat diffractogram to identify any potential effects of preferred orientation in the sample.

New scaning rate that you suggested is possible, except that price of analysis significally jump, almost double since it is longer time. Also I forward them questions from Ravi, I think if they have 2D it would be more expensive, 

Choice of substrate is quartz because it can sustain high temperatures, in contrast with silica, because I prepare my film directly on XRD substrate, 

It shoud be Cu target, 

I dont understand purpose of rotating sample surface?

answer: XRD pattern can show peak of your substrate about 2theta = 20.

Stefan, Si melting point 1,414C, too low?

"New scaning rate that you suggested is possible, except that price of analysis significally jump, almost double since it is longer time. Also I forward them questions from Ravi, I think if they have 2D it would be more expensive,"

X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Worth acquiring for every XRD collection!

(pp. 162-163) 6.3.5. "Comparison between the Photographic and Counter Methods

It is obvious that the Geiger Counter and the ionization chamber have the advantage of precision and sensitivity. They alone permit a quantitative study of scattering. However, point by point measurements in reciprocal space are lengthy, while the photographic method gives directly a picture of the scattering in a single experiment over a large surface of reciprocal space. The resolving power of the film is excellent. Thus, sharply defined scattering regions, for example on rows or on planes of reciprocal lattice, show up very clearly on photographic film but are difficult to detect with a counter.

Let us note also that the counter is "blind". In many cases inaccuracies in the setup produce stray scattering which is easy to detect on the photographic film but which can spoil a series of experiments made with a counter.

The two methods are therefore complementary and it would not be advisable to neglect one in favor of the other. The photographic method is admirably suited to the qualitative exploration of an unknown pattern, since one can then find totally unexpected phenomena. The counter is necessary for quantitative measurements on a pattern which is already known qualitatively."

This was printed in 1962. This has to be considered in light of the present day 2D detectors that combine the benefits of the counter & the film in one. These writings indicate some causes for the present day inertia of moving from the 0D to the modern 2D detectors. The spatial "blindness" of the 0D scintillation counter/detector is the principal reason even experienced experts using XRD are ambivalent about the 0D XRD data/results.

https://www.flickr.com/photos/85210325@N04/10515372183/in/album-72157645018820696/

Dear ian J slipper, do you think something like this? http://www.mtixtl.com/Zero-Si-24D10C1.aspx

"I dont understand purpose of rotating sample surface?"

To detect any presence of "preferred orientation" in the film which will skew the relative intensity & shape of XRD peaks. Depending on how you orient the film w.r.t. the incident beam, "preferred orientation" will significantly affect the conventional equatorial scan, as in your case.

See example below of 2D XRD signal from an Aluminum foil with preferred orientaion compared with conventional equatorial scan DIFFRACTOGRAMS. Please note that the two conventional diffractograms were obtained for two orthogonal positions of the foil w.r.t. the incident beam, i.e., rotated sample (90 DEGREES).

"Choice of substrate is quartz because it can sustain high temperatures, in contrast with silica, because I prepare my film directly on XRD substrate, "

The film morphology and characteristics would depend on several factors including:

• Growth method and parameters.
• Substrate material and crystallographic orientation.
• Choice of substrate is usually based on the coherence desired between film and substrate.

So I suspect switching quartz/silica with Si would change the paradigm significantly.

https://www.flickr.com/photos/85210325@N04/7944785794/in/album-72157632728981912/

thank you for wonderfull answer Ravi,

however,  I have trouble with understand what you mean by 2D detector?

Stefan, yes that was the sort of thing I was thinking of. We use them all the time for very small quantities of powder, but this might give you a better background than the quartz. I have never heated them, but I do have one that is fitted to go into my heating stage - that can go up to 450C. I don't know what temperatures you are looking at.

"what you mean by 2D detector" - Watch the YouTube play list attached below.

https://www.youtube.com/watch?v=JESFFQpwumY&list=PL7032E2DAF1F3941F

I got an answer from them, they dont have any knowledge of 2D, however, they have scintillator detector, which according to video that you provided me it is not same, quite different, I wounder if  this detector can tell valence of Fe.

I understand purpose of orientation now, thank you. 

thin shit of quart is only suitable for way of preparation. but I think it is really good idea to do XRD of only substrate. I would like to know do I need to use same parameters and same instrument for it? GIXRD with same scanning rate, or I can use conventional powder XRD?because powder xrd is for free and I am afraid that only substrate for every sample with double expenses which are already doubled. data can be regarded as accurate even they are not obtain from same machines?

"they dont have any knowledge of 2D" - Pathetic :-)

Are they also oblivious to the use of 2D photographic film in XRD?

" I wounder if  this detector can tell valence of Fe." - Not really! Only the data may, depending on the knowledge level of the analyzer. If the valence of Fe changes the crystallography, then potentially :-)

"I would like to know do I need to use same parameters and same instrument for it?". Yes, preferably!

"I can use conventional powder XRD? because powder xrd is for free". Sure! The only challenge, is to simulate similar penetration depth (diffracting volume) as in the GIXRD. Are you able to adjust Omega (incidence angle) independent of 2-Theta? You'll get a pretty decent idea "for free" :-)

BTW Have you computed the penetration depth for the diffraction geometry you have chosen? This would depend on the incidence angle you used for the GIXRD data besides the X-ray wavelength.

Just remember - what you get for FREE may be worth only what you pay for it, i.e., NOTHING :-)   Just kidding!

Dear Ravi and Ian,

Unfortunately, nothing new happened  I mean, it is more clear that is for sure, but there is only one pick now

So what did you do different for this diffractogram? Looks very different from the original diffractogram. Looking at the profile it appears that you have similar beam conditioning as in the profile shown for the corundum standard powder in the attachment below.

I suspect preferred orientation as the cause of the non uniformity in the two profiles you have displayed.

See if this attachment helps any :-)

Real Time 2D Powder Diffraction - Revolutionizing Data Collection In Your XRD Lab. 75-90% Time/Cost Savings!

https://www.linkedin.com/pulse/real-time-2d-powder-diffraction-revolutionizing-data-ravi-ananth?trk=mp-reader-card

https://www.linkedin.com/pulse/real-time-2d-powder-diffraction-revolutionizing-data-ravi-ananth?trk=mp-reader-card

well, different is speed, I used slower scanning speed, same substrate same condition for preparation. different samples. 

"different samples"?

What is the difference? With slower speed, I'd have expected the peaks to have gotten stronger provided all else was the same including the sample orientation w.r.t. the incident beam. Was it?

Now read the following carefully. This is from a book published in 1962. Please ignore the repetition and redundancy.

X-ray Diffraction In Crystals, Imperfect Crystals and Amorphous Bodies by Andre Guinier. 1962 - Worth acquiring for every XRD collection!

(pp. 162-163) 6.3.5. "Comparison between the Photographic and Counter Methods

It is obvious that the Geiger Counter and the ionization chamber have the advantage of precision and sensitivity. They alone permit a quantitative study of scattering. However, point by point measurements in reciprocal space are lengthy, while the photographic method gives directly a picture of the scattering in a single experiment over a large surface of reciprocal space. The resolving power of the film is excellent. Thus, sharply defined scattering regions, for example on rows or on planes of reciprocal lattice, show up very clearly on photographic film but are difficult to detect with a counter.

Let us note also that the counter is "blind". In many cases inaccuracies in the setup produce stray scattering which is easy to detect on the photographic film but which can spoil a series of experiments made with a counter.

The two methods are therefore complimentary and it would not be advisable to neglect one in favor of the other. The photographic method is admirably suited to the qualitative exploration of an unknown pattern, since one can then find totally unexpected phenomena. The counter is necessary for quantitative measurements on a pattern which is already known qualitatively."

This is precisely what I was referring to when recommending the use of 2D detectors. Modern 2D detectors combine the advantages of the point counter and film in one. The fact is that you must have spent at least 2-4 hours acquiring the 2 diffractograms, I guess. BTW, How long did the 2 scans take? Instead, the cause of the inconsistency between the two scans may become evident with just a few 2D exposures. Thus, avoiding lengthy protracted futile pontification over triviality and ambiguity :-) You can do this with ordinary dental film as well. Got any or is it extinct in your XRD lab? 

In my opinion, you'll learn more about the Nano structure of your samples with a few 2D exposures than all these fancy conventional linear equatorial plane diffractograms collected with the archaic 0D "point/scintillation/proportional" counter.

Best regards!

https://www.linkedin.com/pulse/x-ray-diffraction-crystals-imperfect-amorphous-bodies-ravi-ananth?trk=pulse_spock-articles

https://www.flickr.com/photos/85210325@N04/10515372183/in/album-72157645018820696/

4 hours. 

If they don't know what is 2D exposure there is nothing I can do. 

Is there any other way to determinate differences, except of 2D?

The 2nd profile is not what it should have been. It is possible that during GIXRD the sample surface was displaced a bit and the penetration was not identical and hence poor signal from the film. Sample surface alignment is critical for GIXRD data. Especially, for comparison.

Ian may have some additional ideas to isolate what you are looking for but trying to solve the enigma with ancient tools is a tall order. In my opinion, it would be a huge challenge deconvoluting the effects of sample position, preferred orientation and phase composition from a single conventional linear diffractogram :-)

"If they don't know what is 2D exposure", this is the challenge throughout the XRD community after nearly a century past the Braggs. Sad!

"Is there any other way to determinate differences, except of 2D?". In my opinion, NO! Unless, you do what I recommended earlier on, which would take "lots of time" (huge cost) using the XRD tools you have presently. You'll have to create the 2D data with the 0D detector. Sort of like "pole figure" analysis. Know anything about it?

You may need to learn about the benefits of 2D XRD and teach them :-)

https://www.flickr.com/photos/85210325@N04/10221065324/in/album-72157645018820696/

Stefan, It is difficult to explain why several of the peaks have disappeared! You now have a much better signal/noise, which is good. A while back Ravi mentioned rotating the sample in the holder - did you try that? The other point mentioned in that same post was Fe fluorescence from your sample - I think that is a minor consideration at the moment until we can find out why your peaks have gone, but in future you need to try and use either a different anode (Co) or use energy filtering at the detector - the background counts should reduce with this approach.

http://www.icdd.com/resources/axa/vol46/v46_05.pdf

A two-dimensional X-ray diffraction (XRD2

) system has both the capability of acquiring

diffraction patterns in 2D space simultaneously, and analyzing the 2D diffraction data

accordingly [1-3]. In recent years, usage of two-dimensional (2D) detectors has dramatically

increased due to the advances in detector technology, point beam X-ray optics, and computing

power. The integrated data gives better intensity and statistics for phase identification and

quantitative analysis, especially for those samples with texture, large grain size, or small quantity.

2D detectors can collect diffraction data in a large 2θ range simultaneously without sample or

detector movement. This is extremely important for high-throughput diffraction screening

http://www.icdd.com/resources/axa/vol43/v43_037.pdf

I think this suppose to be some new sort of machine.(more than 16 years old principle :D )  I m not sure if it is available even if it is possible to use I will probably need to learn how to utilise it first, and interpreting. 

Rotating samples will increase my cost drastically, I dont have sufficient funding for even new slower speed.

"either a different anode (Co) or use energy filtering at the detector - the background counts should reduce with this approach"

thank you for suggestion, I will ask if it is possible.

Paraphrasing Andre' Guinier, "if you find the smoke in reciprocal space then you'll find the cigar in real space" (according to my prof. Dr. Tom Tsakalakos of RU who was one of his students). In other words, if the signal is missing in the XRD then most likely the cause in real space is missing :-)

• Maybe the phase is non-existent in the sampling area. (What was your incident beam size approximately?)
• Maybe the film has grown with preferred orientation and the orientation of your sample (w.r.t. the incident beam) creates a attenuation of the signal along the equatorial plane chosen.
• Maybe the film thickness is insufficient to create discernible signal in the convoluted "mess" that a conventional linear diffractogram generally is, compared to the "fluorescence" from Fe in the sample.

You are yet to share with us the following, unless I missed it :-)

If I had limited funds then I'd be accumulating information before blowing my wad. I'd also take a careful closer look at using CHEAP dental film (find a neighborhood old time dentist) and short time exposures than the "blind" costly (hours) diffractogram that you are using :-)

"Rotating samples will increase my cost drastically, I dont have sufficient funding for even new slower speed." Why?  That is a tough way to work with XRD. Both user and facility are clueless. The only way this will work for you is if you learn it well before using.

You may already have done this "sample rotation" inadvertently when you took the 2nd scan . When rotation was mentioned earlier, it was not continuous rotation. That only works for powder samples in a capillary along the diffractometer axis. In this case, the rotation I recommend would be about its surface normal was to isolate any potential preferred orientation effects Just a couple of 90o rotations and quick scans (not slow) would do. I have to assume your sample is "flat". Is it?

Yes my sample ( samples ) are flat.

by sample rotation, you mean how sample was placed in holder? then definitely yes, samples 1 and 2 have different rotation.

only second sample costed 210 euros. I need to repeat them several times, until I can adjust method of preparation. Method of preparation is new, something between arc discharge and mag sputtering, 

prepared on quartz substrate. I provided you with SAED I dont have micrographs yet I will post it us soon as I can ( which again is strongly related to funds :D )

incident beam size between 0.5 and 1 degree

I assume orientation of growth is layer by layer,

"Funds" are FUNDamental to all our existence. Figure out how to squeeze the most out of them :-) 

"incident beam size between 0.5 and 1 degree". I interpret that as incidence angle between 0.5o to 1o. (Did you mean so, or are you talking about the divergence?) That could lead to a significant difference at those angles. Is it prudent to assume that the incidence angles in the two cases you've show are NOT identical? If so, there is no reason to expect the same profile. I suggest you compute the penetration depths at those angles as well. I also suggest you maintain the same incidence angle for diffractograms in order to be able to compare them easily.

"I assume orientation of growth is layer by layer," - Depends on the lattice compatibility of film and substrate. In all likelihood you have "oriented" poly-crystalline morphology in the film.

Also see what happens to a "line source" from a HRXRD beam conditioner when you place a 2D detector at a shallow angle to the beam direction: https://www.flickr.com/photos/85210325@N04/30278571264/in/dateposted/

Is the quartz substrate amorphous, poly or mono crystalline?

BTW you may measure both film thickness and flatness (surface roughness) using NDE XRR (Reflectivity). Limit around 300nm, I've learnt.

https://www.linkedin.com/pulse/modern-real-time-xrr-x-ray-reflectivity-ravi-ananth?trk=pulse_spock-articles

https://www.flickr.com/photos/85210325@N04/30278571264/in/dateposted/

Uhhhhh, sad. I wanted to update this question with rotated samples, but I notice that Ian J slipper passed away, even I never met him, thank you very much for suggestions. Rest in peace good man.

My deepest condolences to his family and loved ones. His proactive participation and contributions on RG will remain for ever. Thanks buddy! RIP

Why is there no reference of him? Really? Can't even find him on RG. Why?

Say hi to my mom for me. She was 84. We'll all be there sooner or later. Let's make the best use of the time we have left in this life. Treat each day as if it was the last. Do your best and be kind like Ian was.

Today is the funeral of a dear aunt, Helen. She was 96. May her soul rest in peace.

https://www.researchgate.net/post/How_do_I_figure_out_the_spatial_thickness_of_the_individual_layers_from_these_not_so_well_resolved_diffractograms?_ntpl%5BactivityCombination%5D=person_like_question&_ntpl%5BactivityId%5D=933699105460229&_ntpl%5BactivityTimestamp%5D=1517052414&_ntpl%5BactorId%5D=11070385&_ntpl%5BobjectId%5D=5a0f3810dc332d16a2752b0a&_ntpl%5Bs%5D=365bff82bfe9af8bf379f2b528b9c5b2d8e8ff9f

If you see in upper right corrner there is part Question Followers... you will see his picture... Long blue hair same as mine) you can click on this image and go to his page Ian J Slipper and will see in memorium, the university where he worked didnt announced, which is rare, but they announced that some fosil got named by him.

In Ian's memory!

https://www.researchgate.net/profile/Ian_Slipper

So, why are his posts from the past deleted? That sounds silly. Is that what happens normally? Is it the family's decision or RG?

I dont know, I would like to know also... this is good question for RG, I would like my profie to keep my name after I passed away

I sort of agree. The information I've shared doesn't change upon my demise. Does it?

Here is the new RG question about this topic:

https://www.researchgate.net/post/What_happens_to_RG_contributions_of_a_member_upon_his_or_her_demise