I'm working on the canted antiferromagnetic multiferroic materials like BFO, DMO thin films. If i want to know the individual spin orientation on the surface of the thin films, whether it is compensated or not, defects at the surface, roughness induced change in spin configuration etc, please suggest me the techniques which can be used to do the same... thank you??
If by "individual" you imply "at the single atom level" then you're asking for a lot. With very smooth surfaces, spin polarized STM (SP-STM) can be powerful, but I see potential difficulties: it is highly nontrivial to characterize the chemical nature of the sites you're probing, it essentially probes the surface layer [unless sub-surface defects produce identifiable signatures, which again requires extremely good surfaces to be recognizeable]. An then, it is sensitive to "only" the spin component along the direction in which the STM tip is magnetized. Doing a sequence of measurement with different magnetization orientations of the tip to gain vectorial information has been done in a number of cases [e.g. in the study of skyrmions] but that probably belongs to the top-notch applications of SP-STM.
On top of that, multiferroics are bound to be insulators (ferroelectricity!) and the STM needs some current flow to work...
Other techniques bear other advantages (using polarized x-rays e.g. [-> magnetic x-ray dichroism] can facilitate obtaining element specific information) but spatial resolution is not to be obtained at the atomic or single defect level. In fortunate cases one may be able to reslove domains and characterize them to some extent. The kind of instrument required would then be a photoelectron microscope, installed at a synchrotron radiation facility.
If by "individual" you imply "at the single atom level" then you're asking for a lot. With very smooth surfaces, spin polarized STM (SP-STM) can be powerful, but I see potential difficulties: it is highly nontrivial to characterize the chemical nature of the sites you're probing, it essentially probes the surface layer [unless sub-surface defects produce identifiable signatures, which again requires extremely good surfaces to be recognizeable]. An then, it is sensitive to "only" the spin component along the direction in which the STM tip is magnetized. Doing a sequence of measurement with different magnetization orientations of the tip to gain vectorial information has been done in a number of cases [e.g. in the study of skyrmions] but that probably belongs to the top-notch applications of SP-STM.
On top of that, multiferroics are bound to be insulators (ferroelectricity!) and the STM needs some current flow to work...
Other techniques bear other advantages (using polarized x-rays e.g. [-> magnetic x-ray dichroism] can facilitate obtaining element specific information) but spatial resolution is not to be obtained at the atomic or single defect level. In fortunate cases one may be able to reslove domains and characterize them to some extent. The kind of instrument required would then be a photoelectron microscope, installed at a synchrotron radiation facility.
The way you formulate it sounds much too affirmative and optimistic to me. You got to discuss that in more detail with someone who is really an expert in SP-STM to find out in detail what they think is doable (under what circumstances) and what isn't. Your original question contains more than one challenge to cope with as I tried to indicate.
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