Effect of sodium carbonate on carbothermic formation of hexagonal boron nitride

The effect of sodium carbonate (Na2CO3) on the formation of hexagonal boron nitride (h-BN) by the carbothermic method was studied by subjecting B2O3 -C and Na2CO3 -added B2O3 -C mixtures to a N2 (g) atmosphere. The Na2CO3 amount in the mixtures was changed in the range of 0-40 wt%. Time and temperature were used as experimental variables. Reaction products were analyzed by XRD and scanning electron microscope. Na2CO3 was found to increase both the amount and the particle size of h-BN, similar to calcium carbonate (CaCO3). Na2CO3 was found to be less effective than CaCO3 in increasing the amount, while it was more effective than CaCO3 in increasing the particle size of the formed h-BN.