Due to absence of long range order, no sharp diffraction peak occurs except a broad halo in  X- ray diffraction pattern of amorphous system. However, in case of crystalline system, sharp Bragg's diffraction peaks are observed. This technique is  commonly used to confirm the amorphous state of the prepared material.

Dear Srinivasarao,

I also agree with the statement, what Dr. A.Kumar elaborated. Another factor:   type of crystalline material?  The crystallinity of the material is observed by the crystallinity index which is the ratio of the measurement of crystallite size from the SEM and from the XRD analysis (Scherrer formula).. If Icry (crystallinity index) value is less than one, then the crystallite size represents monocrystalline material, whereas if Icry is much greater than one the material becomes polycrystalline or semicrystalline.

With regards.

See Dr A. Kumar's answer. The explanation is very valuable.

 Than q u Dr. A kumar..I totally agree to your answer..is there any reported articles to confirm that point.  .because most of the guides not satisfied with that explaination..sir I am not trying to impress you like other...sir your valuable suggestions important for me..i will send the papers reviewer comments for that question within fee days..

Sir than q u for providing such a valuable suggestions..

According to shape how will be we clear its polycrystaline or crystaline.