Elektronen-Spin-Resonanz von Mn²⁺-Ionen im kubischen und trigonalen Kristallfeld des ZnS

Abstract

The Electron-Spin-Resonance of Mn 2+ -ions in synthetic cubic and hexagonal ZnS crystals has been observed at X-band frequencies. At 300°K the following values for the parameters of the Spin-HAMILTONian resulted for cubic ZnS: g=2,0024±0,0003, α= +0,000787 ± 0,000006 cm -1 , A= -0,00640±0,00001 cm -1 . A weak superhyperfine structure due to an interaction of the 3d-electrons of the Mn 2+ -ion with the surrounding Zn 67 -nuclei was also resolved. The influence of stacking faults in cubic ZnS crystals on the position and linewidth of the Mn 2+ -spectrum was investigated in detail. For hexagonal ZnS we found at 300°K: g ∥ =2,0018 ± 0,0003, a— F = + 0,000768 ± 0,00001 cm -1 , α = +0,000735 ± 0,00001 cm -1 , A = —0,00649 ± 0,00001 cm -1 , D= —0,01309 ± 0,00003 cm -1 , P=+ 0,000010±0,000002 cm -1 . The quadrupole coupling constant P was determined from forbidden Am= ± 1 transitions. A strong decrease of the spin-lattice relaxation time of the Mn 2+ -ion was observed in photoconducting ZnS crystals under uv-illumination at 77°K.