EPR Studies on Mn-Doped SnTe Crystals (II)

The X-band electron paramagnetic resonance (EPR) measurements have been carried out over the temperature range from 120 K to 480 K on the powdered samples of the Bridgeman-grown Mn (≦0.5%)-doped SnTe crystals， which are annealed at 500o-600oC under Sn vapor. Some samples show the six hyperfine structures (HFS) in the temperature between 280 and 360 K， but the HFS 1ines disappear under a heat cyc1e between 120 and 480 K. The EPR signals are most1y unresolved and show a broadened line. The temperature dependence of the linewidth suggests that a motional narrowing occurs through a thermal jumping of Mn ions from a lattice site to an interstitial site with activation energies ε=0.5～ 9 × 10-2 eV， which depend on the nominal Mn content. High density of carriers (hole) is found also to be responsible for the linewidth and the jumping energies of Mn ions in the degenerate semiconductor like SnTe