I have prepared some sandwich of metal and ceramic layers. Now I would like to observe their interface, especially in atomic level. I am thinking about using FIB to cut out some samples from the interfacial domain, and then observe the samples by TEM. But these techniques are quite complicated and require alot of time. Would you suggest me another proper method? Thank you in advance!
if you have good Xrays.. Reflectometry, EXAFS .. or high-resolution XPS (with tranverse samples) , high resolution PIXE..
XTEM is of course very fine, but you are right, need to be an expert for preparing your samples.. today's equipment makes it possible in less efforts than 20 years ago.
Thank you very much, Lucas! There is an XPS device in my institute so I am gonna use it to investigate the interface as your comment. However, I am not very familar with XPS technique. Could you please explain more deeply, which information of the interface that I can get from using this XPD technique, and how can I do it? Best regards.
If your X-ray source in XPS is either Al K alpha or Mg K alpha , your maximum top layer thickness needs to less than 10- 15 nm. You need to understand that the signal can come from not only from the interface but may be from above and below interface. On the other if the XPS system is equipped with Synchrotron radiation ( this energy can be varied) so you obtain the information from different thicknesses.
From XPS you can obtain the composition of the materials and also the bonding (oxidation state ) etc.
Thank you for your explanation, Robinson James! Now I understand the XPS technique better. The information from XPS that you said is exactly what I am looking for. I will try this technique with my sample.
the spatial resolution will be the key for you to have the "atomic" resolution you look for. But with a descent XPS and cross-section preparation of a sample, you may scan over the interfaces and have the metal rich regions alterning with the ceramic ones. Be vigilent on the bonding states of each element. If you are lucky, the elements do not mix too much and you have a clear separation of the bonding state in the 2 regions. But have a good focus of the excitation beam (Xray or e-beam for ESCA/AES).
The spatial atomic resolution is probably not reachable with a classical XPS device.
RBS is also something you can try. Japan used to have a lot of ion beams..
Thank you Lucas! Your explanation is really helpful. Now I realise what are the next steps I should follow in this research. I will try with XPS first and think about using Rutherford backscattering spectrometry.
To achieve "atomic" level you want, i personally prefer TEM. From what you described of your sample, it seems regular TEM sample preparation method (vs FIB) should be sufficient. By regular method, i mean preparation by dimpling and ion milling. this method is less complicated than FIB and much cheaper as well, although still takes a bit of practice.
It may be very efficient to use high resolution electron microscopy to visualize the atomic arrangement. You should first find a sufficiently large metal single crystal about the interface and cut by spark erosion the TEM disc parallel to a low index atomic plane(close-packed plane for instance) in the metal at the interface. You should then electropolish the disc by the standard jet technique (use the TEGART to find the appropriate electropolishing solution) and further thin by the ion thinning. The result of the observation would be very nice.
if you have access to a FESEM/FIB dual beam instrument it will take at most 1 hour to get your answer. Revealing the layers by dual beam system is much more easier than TEM also you don't need to prepare TEM sample. But for higher resolution you should absolutely coat your sample with Au-Pd otherwise you cannot reach higher magnifications.
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