Thermophysical behavior of boron nitride and boron trioxide ceramics compounds with high energy electron fluence and swift heavy ion irradiated.

Abstract

We report differential scanning calorimetry (DSC) studies of boron nitride and boron trioxide compounds under different irradiation conditions. In the present work, boron nitride (h-BN) (purity of 99.8% and density of 2.29 g/cm3) and boron trioxide (B2O3) (purity of 99.5% and density of 3.10 g/cm3) samples were irradiated by using high intense electron beam and swift heavy ions irradiation. Electron beam irradiation of the samples was carried out at the different electron fluence of 4.16 1016, 1.20 1017 and 1.03 1018 cm2 with energy of 2.5 MeV. Whereas the swift heavy ion irradiation of the samples was carried out using 132Xe ions with energy of 167 MeV/u at the different fluence of 5 1012, 5 1013 and 3.83 1014 ion/cm2. The thermal parameter changes with a differential mechanism under different irradiation conditions were investigated. In the DSC curves at the low temperature for initial and irradiation samples do not undergo phase transitions. However, at the 100 T 300 K temperature range widely changed the mechanism of the heat flow rate, specific heat capacity and thermodynamic functions in the boron nitride and boron trioxide samples is a more completed. In addition, for each of irradiation fluences, the calculated thermodynamic functions and specific heat capacity was found to increase from 0.002 J/g‧K to 0.08 J/g‧K as the irradiation electron fluence increased. For swift heavy ion irradiation, the specific heat capacity was found to increase from 0.005 J/g‧K to 0.06 J/g‧K. The results have revealed that there was a thermodynamic change. Keywords: Boron nitride, Boron trioxide, High energy electron beam, Swift heavy ion irradiation, Specific heat capacity, Entropy