check this paper , hope it helps

Article EBSD as a tool to identify and quantify bainite and ferrite ...

You should use STEM-EELS mapping.

XRD, HRTEM, STEM-EELS as well as advanced Raman spectroscopic techniques are suitable for the determination of C and N inside the crystal.

@ Md. Abdur Rahman,

Inside the crystal is OK. But can XRD tell the C or N at dislocations or GB? If it so, then pls. provide some method/software/literature where somebody did this.

Simply, using high resolution SEM-EDX, it is possible to identify trace elements with locations.

Dear @ Md. Animul Islam Mraci, thanks for the suggestion. But I don't think that any high resolution SEM-EDX has resolution limits in nano meters, to detect the change in composition along dislocation. Moreover we are also unable to see any dislocation in SEM . But I can try TEM-EDX.

Go for Raman or XRF to determine lighter elements

XPS and STEM(with elmental mapping) are helpful to evaluate the lighter elements in sample.

You did not say what small is so it will be difficult to give precise information on characterization techniques. If your aim is to do identification on the phase then your technique should have the resolution needed for your size range. EBSD is typically good down to 100 nm as long as the phase is crystalline. TEM is very good at 1-100 nm size phases/particles. There is also a new technique that is TKD which uses EBSD on a prepared TEM sample in a SEM. There have been some very good results reported with this method on interstitials in steels, I currently do not have the publications in front of me at the moment.

The most chemically sentive methods for local determination of segregated atoms or ions are analytical STEM (using EDX and/or EELS) and atom probe tomography (APT).

Thanks @ Clarissa A Wisner for your input, I feel that what an EBSD can give we can obtain that from XRD also. Moreover our main aim is to find the composition at dislocation and interfaces and GBs, which are much smaller than 100nm. and we also not obtain any crystalline nature along these defects.

Thanks @ Thomas Walther, I will try EELS. We actually not have APT facility, may be in future we can collaborate with some labs for it.

In the XRD we will not be able to find ,But in the HRTEM with the Cs corrected Equipped with the EELS technique we can find these elements.

https://science.energy.gov/bes/highlights/2018/bes-2018-08-e/

Thanks @ Prof. Raabe, APT is unarguably one of the best technique and it took the characterisation to much advanced level. I will definitely go through all the literature suggested by you.

Agree with @ Prof. Raabe, the most precise for simultaneous crystallographic and chemical characterisation would be: site-specific lift-out sample prep. by FIB - attach sample to TEM grid - TEM tomography - APT. Or less precise: attach sample to Si array - TKD straight after milling - APT.

It Is hard to retrieve crystallographic data from ferritic samples in APT. However, it is possible when the temperature of probing as low as possible and you are guided by other techniques.

Also, C content possible to measure by EPMA, as example I attached paper by prof. Furuhara's group.

There is no all-in-one technique to solve what you wanted to do. One has to be clear of or analyse which is the most likely beforehand. For interstitials, please refer to ABF-STEM + complementary EELS/EDX-STEM; for interfaces, please refer to APT or EELS/EDX-STEM; for segregation at dislocations or faults, please refer to either EELS/EDX-STEM or APT; for voids (relies on which scale), one has to be careful of relevant analysis under appropriate, no matter what technique one would like to apply.

Looking for light elements segregated at grain bounderies, is an extremely difficult task with STEM/EELS, since the the boundary is only a few nanometer thick and rarely orientated parallel to the beam. To my my knowledge, the only way is to rock the grain boundary and aquire a HR EELS linescan, say, every 1 degree. You should also be extremy carefull interpreting C without a plasmacleaning prior to STEM. As mentioned earlier. APT is the way to go

I hope, preliminary analysis using EPMA would yield better results for lighter elements upto ppm level detection with ZAF correction.

Dear Arul, for overall composition EPMA is good, but for zooming in the EPMA at dislocation and interface is bit difficult. I don't know if there is any new advancement in EPMA techniques or combination of two technology to achieve this.

In addition to the suggestions of Prof Dierk Raabe and others, optical emission spectrometry (OES) can be employed to determine the amount of C and N.

Check out this publication:10.1007/s11661-018-4750-9

Thanks @ Wangzhong Mu for your suggestion.

APT is very powerful to visualise chemical enrichment for all types of elements (a major advantage over other techniques) but is very difficult to quantify, and for atomic site identification (lattice site, anti-site, interstitial etc.) the spatial resolution is not good enough - you can get lattice plane resolution usually only in one direction (perpendicular to the sputter direction) but not in the vertical plane. Also, statistics is hampered by non-unity and element-specfic detection sensitivity.