Low-Frequency Raman Spectrum of Bulk Zn0.984Co0.016O Crystal

W. Szuszklewicz , A. Lusakowski , J. F. Morhange (1) , Z. Colacki , M. Arciszewska , B. B. Brodowska , M. Kanehisa (1) , M. Klepka , W. Dobrowolski

1 INSP - Institut des Nanosciences de Paris

The influence of possible presence of Co2+ ion pairs in a bulk Zn1-xCoxO mixed crystal on the low-frequency part of the Raman spectrum is discussed. Two effects can be taken into account in the theoretical considerations when analyzing the energy level scheme corresponding to Co ions. The first is a local lattice deformation in the vicinity of Co2+ ion due to a presence of the second ion, smaller than the host ZnO lattice cation. Such deformation creates a trigonal field, which can only slightly modify the energy levels of v ion. The second effect, which results from an antiferromagnetic superexchange interaction between two Co2+ ions is responsible for a new set of energy levels. The Raman data taken at low temperature on the sample corresponding to the composition x = 0.016 demonstrated the presence of two structures at about 6 cm(-1) and 13 cm(-1). These structures may be interpreted as electronic transitions between the ground state and the first excited state of a single Co2+ ion in the substitution site of ZnO lattice and as a similar transition for Co2+ ion pair, respectively.

Domaines: Matière Condensée [cond-mat]

W. Szuszklewicz, A. Lusakowski, J. F. Morhange, Z. Colacki, M. Arciszewska, et al.. Low-Frequency Raman Spectrum of Bulk Zn0.984Co0.016O Crystal. Acta Physica Polonica A, 2009, 116 (1), pp.103-106. ⟨hal-01229256⟩