"any sample"? That's a pretty general question. So, generally, diffraction techniques should be very helpful in phase identification. XRD may be the simplest of them because sample preparation is relatively trivial. If you don't want / can not use XRD, you may try with TEM (transmission electron microscopy). The sample preparation is much more tedious and time consuming, but thousands of such experiments have been carried out with TEM. In the simple diffraction mode, you will observe the reflexes formed by electrons diffracted from crystal planes, similarly to XRD. The analysis of several electronograms obtained for different crystal orientation should give enough information about interplanar spacings and angles between crystalline planes. From there, there are just a few steps from phase identification. Remember to check the chemical composition of the sample before starting the analysis, in order to reduce the number of possible phases that you will find in the diffraction databases.

In addition to TEM, as described by Jaroslaw, neutron diffraction is also a practical method, although not so widespread in use (because neutrons are more difficult to produce in large quantities.) Data analysis is practically same as for XRD.

You can use TEM (transmission electron microscopy), but XRD technique remains the easiest and most useful

I agree with Jarosław Ferenc and w.s.l. Boyer .

Dear Lyes Benharrat

It depends on the material to be characterized and its adaptability with the characterization technique that will be used. The RAMAN technique could also be used to identify the phase structure. The molecules of a given structure vibrating at a given frequency, so by determining this frequency you can get an idea about the phase structure of your material.

Hi Lyes Benharrat

Electron diffraction can be used to identify crystal structure and it's complementary to X-ray diffraction. another technique is neutron diffraction but i think rarely utilized. The last one is Raman, the powerful tool that can provide information about phase, structure, secondary phases, and crystal quality.