The intensity of peaks in XRD analysis is proportional to the amount of molecules or crystals with a specific spacing. The width of peaks is inversely proportional to crystal size, with thinner peaks indicating larger crystals. Broader peaks suggest smaller crystals, defects in the crystalline structure, or an amorphous sample.
The X-ray diffraction pattern of a material can reveal information about the crystalline/amorphous structure and phase composition of the materials. In the case of biopolymers, they typically show broad peaks due to the overlapping of different crystal planes within the polymer chains and also because of their semi-crystalline nature whereas, the carbonates, typically show well-defined and sharp diffraction peaks due to their highly ordered structure.
Thus, depending on the relative quantities of the two components and the level of crystallinity in each component, the diffraction spectra in a biopolymer-carbonate composite may exhibit both broad and sharp peaks. The peaks may also show shifting or broadening due to the interaction between both components in the composite. Based on this spectral analysis, one can determine the information regarding the phase composition and crystalline structure of the material. Therefore, the XRD spectra shared above have sharp and intense peaks showing high crystallinity of the material but in order to determine the phase composition, one needs to match the peak positions with standard reference data files (JCPDS file) of the same.
Hope this information might help you for your XRD analysis.