Structural, optical and magnetic properties of polycrystalline Zn _(1-x)Mn_xO ceramics

摘要

Structural, optical and magnetic properties of polycrystalline Zn _(1-x)Mn_xO ceramics are studied. X-ray diffraction patterns reveal that Zn_(1-x)Mn_xO samples with x≤0.04 are single phase in the wurtzite structure. The increase in Mn concentration with x>0.04 leads to the formation of tetragonal ZnMn_2O_4 spinel. This changes the peak position and intensity of ultraviolet emission centered at about 379 nm. Under an excitation wavelength of 488 nm, we have observed luminescence emission peaked at about 650 nm, which is related to electronic transitions of Mn~(2+) ions in the ZnO crystal field. An incorporation of Mn dopants into the ZnO host lattice and the formation of ZnMn _2O_4 are also confirmed by Raman scattering spectroscopy, based on the feature of additional modes. Electron spin resonance study exhibits the existence of Mn~(2+) and Mn~(3+) ions in Zn _(1-x)Mn_xO. The variation of Mn content (x) changes the concentration of these ions, and thus influences the resonant parameters.