Synthesis and characterization of nanocrystaline hexagonal boron nitride powders: XRD and luminescence properties

Nanocrystalline hexagonal boron nitride powders (h-BN) were synthesized from urea and boric acid followed by pirolysis and subsequent heat treatment in nitrogen atmosphere. Materials have been analyzed by means of X-ray diffraction, Photoluminescence and Field emission electron microscopy methods. Obtained results show that starting h-BN powder, synthesized at 750 °C, is composed of ~11 layer crystallites with average crystallite thickness and crystallite lateral size of 3.94 and 10.4 nm, respectively. A broad emission and intense luminescence intensity were observed due to the large atomic disorder. Higher annealing temperature increases crystallite size and turbostratic h-BN transforms to well crystallized h-BN at 1500 °C.