The JCPDS pdf-database aims to contain all published powder diffraction pattern as well as patterns calculated from all known crystal structures. Thus, if it is truly a compound not in the data base (not, e.g., a mixture of two compounds), it would be a new compound. Thus one has to apply the normal toolset for structure determination from powder. First, taking a high-quality diffraction pattern (high resolution, low background, no systematic errors). Second, indexing the Bragg peaks using appropriate software (e.g. N-Treor), also determining the possible space-groups. Third, chemical composition analysis. Fourth, structure determination with one of the many available methods.
The JCPDS pdf-database aims to contain all published powder diffraction pattern as well as patterns calculated from all known crystal structures. Thus, if it is truly a compound not in the data base (not, e.g., a mixture of two compounds), it would be a new compound. Thus one has to apply the normal toolset for structure determination from powder. First, taking a high-quality diffraction pattern (high resolution, low background, no systematic errors). Second, indexing the Bragg peaks using appropriate software (e.g. N-Treor), also determining the possible space-groups. Third, chemical composition analysis. Fourth, structure determination with one of the many available methods.
If you have a small single crystal sample instead of a powder sample collect a single crystal reflection data set, determine lattice symmetry (unit cell, Bravais lattice) and calculate the position of the atoms in the unit cell (crystal structure) by evaluating the reflection intensities which are proportional to the square of the structure factor which contains the atom positions. This complex calculations (direct methods) are done easily by software like SHELXL from George M. Sheldrick.
Generally, when a deal with a new material, i begin with the simmetry: it is cubic, tetragonal or hexagonal? These are structures that have some particular behavior (cubic shows high symmetry so it have little peaks, as tetragonal and hexagonal). In the case or monoclinic or triclinic it is more complicated. Also it is necessary to discard any secondary phase, this will be relatively easy since any possible binary is in the JCPDS pdf database.
Please, show the diffraction pattern and the nominal composition for more help.
Best regards,
Pedro
Daniel sir,
your answer shows a path, since I am also facing same problem. Can you suggest what kind of chemical analysis can be done? Also suggest me that what other structure determination technique can be done, as the peaks are very small than the substrate peak? I am working on thin films
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