Band gap of triglycine selenate,triglycine fluorine beryllate,triglycine sulfate and its variation under γ-irradiation

The band gap for three ferroelectrics (triglycine selenate, triglycine fluorine berryllate and triglycine sulfate) is determined using an optic method. A shift of self-absorption edge towards longer wave lengths is observed when exposed to irradiation by γ rays with a dosage of ∽ (2 ÷ 7) · 10⁷ r as well as corresponding decrease of band gap. The observed changes are connected with the chemical nature of the studied substances.