Gamma irradiation-induced phase transitions of boron nitride nanoparticles

Recently different methods are explored to synthesize suparhard orthorhombic boron nitride (o-BN) nanomaterials which have a wide range of industrial applications in the sensors, fiters, battery, biological applications and deep ultraviolet light emitting diodes. In this research work, a simple method is reported to synthesis of cubic boron nitride nanoparticles (c-BNNPs) via gamma irradiation induced phase transition of hexagonal boron nitride nanoparticles (h-BNNPs). X Ray Diffraction (XRD) and Raman Spectroscopy results confirmed the phase transition of h-BNNPs to o-BNNPs at the dose of 21 kGy. At the dose of 24 kGy, high resolution transmission electron microscopy (HRTEM) results showed that phase of hexagonal boron nitride nanoparticles (h-BNNPs) are transformed to B₂O₃ whereas at lower dose (18 kGy), coalescence of hexagonal boron nitride nanoparticles (h-BNNPs) is observed through high resolution transmission electron microscopy (HRTEM) results. X-rays diffractions (XRD) results showed that grain size of hexagonal boron nitride nanoparticles (h- BNNPs) is increased. Mechanism of phase transition and coalescence of hexagonal boron nitride nanoparticles (h-BNNPs) are explained via high energy and short wavelength gamma radiations act on B-N covalent bond isotopically.