The fine structure levels and spin-singlet contributions to zero-field-splitting parameters of Cr2+ ion in CdGa2S4

A theoretical investigation is reported of the fine structure levels and the spin-singlet contributions to zero-field-splitting (ZFS) parameters for Cr2+ ion in CdGa2S4 crystals. Firstly, the complete energy matrix including all spin states for a 3d 4 ion in tetrahedral D 2d symmetry is constructed according the double-group chain in the strong-field scheme. Then, by diagonalizing the complete energy of electron–electron interactions, the crystal field and the spin–orbit coupling for the Cr2+ (3d 4) ion in CdGa2S4 crystal, the fine structure levels and the spin-singlet contributions to ZFS parameters a, D and F are calculated. The results show that the spin-singlet contribution to D is negligible, but the contributions to a and F are very important. So, to obtain more accurate ZFS parameters for 3d 4 ions in the tetrahedral crystals, all spin states should be considered.

[1]  K. Xiao-yu,et al.  EPR theoretical investigation of substitution site and local lattice structure of tetragonal Cr2+ in cadmium thiogallate , 2006 .

[2]  A. Ozarowski,et al.  Tunable-frequency high-field electron paramagnetic resonance. , 2006, Journal of magnetic resonance.

[3]  Sudhir B. Trivedi,et al.  Comparison of the optical properties of diffusion-doped polycrystalline Cr:ZnSe and Cr:CdTe windows , 2006 .

[4]  L. Martinelli,et al.  Jahn-Teller effect in the emission and absorption spectra ofZnS:Cr2+andZnSe:Cr2+ , 2004 .

[5]  A. G. Avanesov,et al.  High-frequency EPR of Cr2+ ions in CdGa2S4 , 2003 .

[6]  V. Tarasov,et al.  Jahn-teller chromium ions in CdF2 and CaF2 crystals: An EPR spectroscopic study in the frequency range 9.3–300 GHz , 2002 .

[7]  A. Barra,et al.  Is the axial zero-field splitting parameter of tetragonally elongated high-spin manganese(III) complexes always negative? , 2002, Journal of the American Chemical Society.

[8]  J. Maan,et al.  High-magnetic-field EPR of Cr-based diluted magnetic semiconductors , 2000 .

[9]  A. Gavaix.  Studies of the Jahn-Teller system , 1998 .

[10]  Yi-Yang Zhou,et al.  Excitation levels, fine-structure splittings of ground state and EPR parameters in ZnSe:Cr2+ , 1998 .

[11]  C. Rudowicz,et al.  Crystal field and EPR analysis for 5D (3d4 and 3d6) ions at tetragonal sites: Applications to Fe2+ ions in minerals and Cr2+ impurities in semiconductors , 1996 .

[12]  Alonso,et al.  Continuous-wave and pulsed EPR studies of Cr2+ defects in CaF2. , 1996, Physical review. B, Condensed matter.

[13]  Zhou,et al.  Zero-field-splitting parameters of Cr2+ ion in GaAs. , 1995, Physical review. B, Condensed matter.

[14]  Jiang,et al.  Contributions to zero-field splitting from spin triplets of 3d4 and 3d6 ions in tetragonal symmetry. , 1994, Physical review. B, Condensed matter.

[15]  Zhou,et al.  Spin-triplet contribution to zero-field splittings for 3d4 and 3d6 ions at tetragonal sites. , 1993, Physical review. B, Condensed matter.

[16]  C. Rudowicz,et al.  Crystal field levels and zero-field splitting parameters of Cr2+ in the mixed system Rb2MnxCr1−xCl4 , 1993 .

[17]  R. D. Groot,et al.  Electronic band-structure calculations of some magnetic chromium compounds , 1989 .

[18]  U. Kaufmann.  EPR and optical absorption of Fe + , Fe 2 + , Fe 3 + , and Fe 4 + on tetragonal sites in CdSi P 2 , 1976 .

[19]  J. Griffith,et al.  The Theory of Transition-Metal Ions , 1962 .