The
broadening of the peak at 2θ≈32.2°, which would correspond
to the (320) plane of the o-Zr3N4 structure, could result from the
small grain size and/or some reduction of the crystalline volume
fraction of the coating, or even to a superposition of several
peaks predicted in this region for this structure. The indexation
of a particular crystalline structure to this sample is very difficult
to fulfil due to the reduced number of diffraction peaks,