Unoccupied orbitals of 3d transition metals in ZnS

Potential applications in magnetoelectronics have created interest in transition metal doped semiconductors. Wide-gap magnetic semiconductors, in particular, are promising candidates for reaching high Tc. As prototypes we have studied [1] a series of 3d transition metals (Ti, Mn, Fe, Co, Ni) embedded in single crystal ZnS. Their electronic structure is determined by NEXAFS with fluorescence detection, which suppresses the background from the host and eliminates charging problems. The spectra exhibit considerable fine structure, which allows us to determine a tetrahedral crystal field spitting in the range 0.5eV < 10Dq <0.8eV. 1. V. Pérez-Dieste et al., Phys. Rev. B, submitted.