Peculiarities of Radiothermoluminescence in Gamma Irradiated Boron Silicates

Abstract

UDC 546.28:535.343

Peculiarities of radiothermoluminescence (RTL) in gamma irradiated boron silicates are investigated in the range of temperatures 80–300K. It is found out that RTL curves B₂O₃/SiO₂ are characterized by the presence of a narrow peak at T = 136K with the energy of activation E_a = 0.16 eV, and of a wide asymmetric peak at T = 178K with E_a = 0.28K, with a shoulder at T = 205K with E_a = 0.32 eV. It is established that the RTL peak at 136K is attributed to the radiating electronic centre, while peaks at 178K and 205K – to the hole centres of B^{3 +} and B^{4 +} types, respectively. It is shown that in maintaining B₂O₃ in SiO₂ ~ 1.5 mas. %, the irradiation in small doses of D_γ ≈ 0.5–30 kGy leads to the transition of the coordination environment of boron from tetrahedric into the trigonal one. At D_γ ≤ 30 kGy, the radiation-proof stable structure of boron silicates with the maximal content of trigonally coordinated boron atoms is formed.

Keywords: radiothermoluminescence, boron silicate, gamma-irradiation, coordination of boron, IR-spectroscopy.