I am mainly working on magnetism but mostly having problems while their characterization using TEM and XRD could you please tell me that how can i interpret my results and what are the possible problems and newbies occurred while doing magnetic material characterization by TEM XRD and what are the other techniques of magnetic material characterization for defining their magnonic structure and domains................
Please specify the problem. With only this small amount of info I can't really think of any issues arising from XRD measurements that could be attributed to the magnetic properties of the material.
How did you take your TEM images? Some more clarity is required for suggestions
yes anil......he would have got beam deflection. He need to explain the specimen preparation and the material. SADP will be difficult, I feel.
What kind of problems did you already face? Can you please explain? Actually this very small information can't let people clearly know about the difficulty you faced.
I dont think that there is any issue in doing the XRD measurement of magnetic sample, even now a days people are doing XRD measurement in the presence of very high magnetic field too. I have also performed the XRD measurement of a magnetic sample even in 8T magnetic field and no issue I have found. In TEM, magnetic lens are used to focus the electron beam so by using he magnetic sample it can harm the lens and so that's why people at some places doesn't entertain the magnetic samples. Apart from XRD, you can also perform neutron diffraction measurement of your sample to see the structure and magnetic properties as well.
One problem you can get in the TEM is your sample flying away, only to end stuck to the polepiece, it happened to us and it was a hell of a mess.. Anyway, generally speaking I think you'll find it more difficult to get good images, but for EDS analysis it should not be an issue..
With XRD you can index the patterns of the peaks and also you can identify them according to the structure. While getting images in TEM do focus on the magnification times. so that you can easily get actual size of the particles of your samples..
In TEM you can do various techniques to obtain magnetic information of the sample. First you should not put in the specimen with objective lens on to preserve the magnetic native state. else the ~2T magnetic field of the objective lens is destroying the magnetic domain structure. If you want to do EDX chemical analysis objective lens has to be switched on so that the backscattered electrons cannot reach the detector and are stopped by the field power. Proper sample fixation on the holder is mandatory, because normally the sample will be lost in the loadlock when going from earth magnetic field to ~2T.
If you are interested in the magnetic structure Lorentz microscopy with Lorentz lens can visualize in Foucault or Fresnel mode magnetic structures in TEM mode. typical resolution is around a few nm. In STEM magnetic domains can be studied using Differencial phase contrast with a segmented STEM detector, measuring the deflection of the diffraction pattern due to the magnetic field. Last option is holography in combination with field free Lorentz mode to get magnetic structure images.
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