EPR Spectroscopy of Mn²⁺ Cations in Chalcopyrite CuGaSe₂ Matrix

Abstract—Manganese-doped semiconductors CuGa_1 – xMn_xSe₂ (x = 0.02–0.20) with a chalcopyrite structure have been studied by EPR spectroscopy. For all samples, a singlet signal with g factor equal to ~2.00 is observed, the width of which decreases with an increase in the manganese concentration from 22.5 to 16.2 mT. For the most diluted sample with x = 0.02, a fine and hyperfine structure of the spectrum of the Mn²⁺ ion is observed in the high-frequency W-range (93 GHz). The hyperfine splitting parameter A has been estimated and the longitudinal and transverse relaxation times at 10 K have been determined by the electron spin echo method.