Effect of sodium carbonate on carbothermic formation of hexagonal boron nitride

Authors: UĞUR AKYILDIZ, NACİ SEVİNÇ

Abstract: The effect of sodium carbonate (Na_2CO_3) on the formation of hexagonal boron nitride (h-BN) by the carbothermic method was studied by subjecting B_2O_3-C and Na_2CO_3-added B_2O_3-C mixtures to a N_2(g) atmosphere. The Na_2CO_3 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. Na_2CO_3 was found to increase both the amount and the particle size of h-BN, similar to calcium carbonate (CaCO_3). Na_2CO_3 was found to be less effective than CaCO_3 in increasing the amount, while it was more effective than CaCO_3 in increasing the particle size of the formed h-BN.

Keywords: Hexagonal boron nitride, carbothermic formation, sodium oxide, particle size

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