but neither do they exhibit the vibration bands typical of ZrO2 and B2O3.
As shown in Fig. 7, this scenario is also valid for the Raman spectra,
despite ZrB2 not being Raman active [22] which in principle should have facilitated the detection of the Raman peaks of ZrO2 and B2O3.
Thus, it can be concluded that the FTIR and Raman spectroscopic studies are unable to conclusively discriminate the presence of the concentrations of ZrO2 and B2O3 formed during the high-energy ball-milling of ZrB2 in air.