ESR OF AN MN2-S2- COMPLEX CENTER IN KCL CRYSTALS()

Electron spin resonance of MnS-doped KCl crystals has been investigate d. It was found that as-grown samples show a simple spectrum looking l ike being constructed from eighteen resonance lines. The spectrum was very stable at room temperature and the same spectrum was also obtaine d after annealing of quenched samples which exibit only well-known spe ctra due to two types of Mn2+-vacancy complex centers. Such a spectrum characteristic of as-grown samples was analysed using a model of an M n2+-S2- complex center in an orthorhombic crystalline field basically with principal axes along (100) cubic crystal axes: two of which are t ilted by 100 from (100) crystal axes. When as-grown samples were coole d down to about 150K, the tilt angle decreased to zero and the crystal line field surrounding the center changed from orthorhombic to nearly tetragonal. It was also found that the Mn2+-S2- complex center respons ible for the 18-line spectra disappears by uv irradiation.