Radiation effects in Li2B4O7 oxide crystals

The lithium tetraborate single crystal has been irradiated by neutrons and the optical properties of these crystals are studied. Irradiation induces o ptical absorption bands at 42 000, 33 000, and 20 000 cm(=1). The intensiti es of these bands depend on the energy of the neutrons, on the irradiation temperature, and on the presence of an external electric field. An applied electric field induces the displacement of charged particles, creating the micrononhomogeneous regions in the crystal leading to a decrease of the int ensities of the absorption bands. It has been established that the irradiat ion damages not only the surface of the crystal but also the deeper layers. (C) 2000 Elsevier Science B.V. All rights reserved.