ANHARMONIC EFFECTS IN THE ELECTRON SPIN-LATTICE RELAXATION OF RADIATION DEFECTS IN POTASSIUM SELENATE AND ROCHELLE SALT SINGLE CRYSTALS

The spin-lattice relaxation method is rather informative in investigations of peculiarities of vibrational spectra in crystals alongside with such methods as submillimeter spectroscopy, Raman spectroscopy and infrared light absorption [1]. . We have measured the spin—lattice relaxation time Τ1 of paramagnetic radicals (SeO3)being formed as a result of γ-irradiation in a potassium selenate (K2SeO4) single crystal which has been grown at the University of Saarbrucken (Germany). As it is known [2], the γ-irradiation of K2SeO4 leads to formation of few different radical types. We have studied the radical (SeO3) which causes the most intensive EPR line. The dose of irradiation was up to 5 Mrad. Measurements have been carried out in the temperature range between 4-180 K at the frequency of 9.4 GHz by means of the electron spin echo method at Leipzig University and using pulse saturation method at Kazan University. The experimental data are compared with those we obtained recently [3] in Rochelle salt with the chemical composition NaΚC4H4O6• 4H2O. The study