The angles in the XRD pattern of the prepared hematite compound matches with JCPDS-890599. But the intensity of (104) is less than (110), whereas in the hematite XRD data, intensity of (104) is greater than (110). Does this mean that my compound is not alpha phase?
Might be, might not be. Ideally, the intensities are defined by the structure of the phase. Their relative values should be constant and can and is used in the process of phase identification. However, a number of effects can change the peak intensity. Most important in the context of phase analysis is preferred orientation resulting from the shape of the crystals. Hematite in particular can form tabular plates vertical to c. This would tend to increase the intensity of peaks with high Miller index l.
Might be, might not be. Ideally, the intensities are defined by the structure of the phase. Their relative values should be constant and can and is used in the process of phase identification. However, a number of effects can change the peak intensity. Most important in the context of phase analysis is preferred orientation resulting from the shape of the crystals. Hematite in particular can form tabular plates vertical to c. This would tend to increase the intensity of peaks with high Miller index l.
The PDF certainly contains several entries for hematite which are all based on published experimental data. All of them will have very similar peak positions but they may be remarkably different in their relative intensity for hkl. This is caused by the above mentioned preferred orientation commonly described as texture of a powder sample. Especially in case of preferred cleavage planes or ideally grown crystallites in powder it is very difficult to get samples which do not show any texture. This is a big problem during structure refinement using the Rietveld approach. Therefore I would say, your peak positions are quite significant if you practically know which type of phase you have. It cannot anything exotic, and slightly different phases would also show visible changes in peak positions. But for your safety simply keep in mind, that a phase is not only described by peak positions but also have to match (ideally) the expected phase-specific intensities. If you wouldn't know anything about your phase, the question mark would be definitely bigger since the peak positions are exclusively defined by the translation lattice of the crystal, and at last theoretically a lattice could be also very similar for another phase. But then the intensities are usually entirely different. (Of course, exceptions confirm the rule. :-) )
The JCPDS data is a result of perfectly powdered sample (random orientation of crystallites), whereas in reality, there is no way to have 'perfect' powder. Hence the peaks intensities will differ from the JCPDS data, and the difference increases with your crystallite size.
In addition, you may also take a look at the integrative area of the respective peaks, rather than the intensity (peak height). Sometimes, even though the peak height is low, but the integrative area remains unchanged due to the enlarged peak width, which again results from the imperfection of our sample.
It depends on peak position and (hkl) planes, Miller indices. Whether it may be crystalline, polycrystalline or mix phase. Peak width reflects its Crystallite size and nanostructure and peak intensity reflects compound contents in samples.
The peak intensity, may indicate the orientation of a material. The higher peak intensity suggests the higher crystallization (micro size)
The single peak itself gives information about the microstructure of your sample as others correctly stated. It might be helpful also consider the relative intensities of the peaks. Sometimes you might have strong anisotropy or orientation which alter the theoretical peaks intensities. This may happen for example when your powder is in form of platelets
the intensity of the XRD peaks gives idea about the number of crystallites which are deposited in this direction. you may study in this case the preferential growth orientation of the crystallites. Good luck
As Andrea mentioned, the powder is in the form of plates. And regarding the phase, I confirmed it by Raman spectroscopy.
Thank you all for your valuable answers.
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