Investigation of colouring processes in γ-irradiated LaMgAl11O19 single crystals

Investigations of color centres in γ-(Co60, 300 K, fluence: 102-107 Gy) and X-irradiated (0,5 BSV-2 with tungsten anticathode, V=50 kV, I=10 A, σ=10 min, T=80 - 290 K) LaMgAl11=19, grown by horizontal-directed crystallization, are carried out. It is shown, that space charge, the dispersion velocity of which is determined by the sample temperature, emerges in LaMgAl11O19 crystals during γ-irradiation. Five additional absorption bands, thermal decomposition of which occurs at 650 K, are formed within 17000 - 25000 cm-1 field. Bands with maximums at 41000 and 48300 cm-1 correspond to electron centres, and at 23000, 28600, 35000 cm-1 - to hall color centres. EPR-investigations have disclosed three types of paramagnetic fields, one of which belongs to Cr3+ not controllable impurity. It is established, that Nd3+, Cr3+ ions introduction in LaMgAl11O19 crystals increases essentially their radiation resistance