Magneto-reflectance effect in ZnO and ZnO:Mn ceramics

The effect of a magnetic field on the infrared reflectance spectra of undoped and manganese doped ZnO ceramics has been studied. In the undoped samples, an increase in the reflection coefficient was found mainly in the spectral region ν > 580 cm −1 with a slight change in the residual rays range. In the manganese-doped ceramics, the magnetic field results in an increase in the reflection coefficient mainly in the residual rays interval while in the high-frequency region the changes are present also. Based on the modeling of the experimental spectra, it was determined that in the undoped samples, the magnetic field leads to a noticeable increase in the plasmon damping coefficient with an almost unchanged phonon one. In the case of ZnO:Mn ceramics, in addition to an increase in the plasmon damping coefficient, there is a significant decrease in the phonon ones. It is proposed that for the undoped samples the dominant effect is an increase in the effective electron mass, which also occurs in ZnO:Mn samples. In the case of Mn doped samples, it is assumed that the decrease in the phonon damping coefficient may relate to an appearance of defects causing the phonon scattering and reducing their effect in a magnetic field. • Magnetic field affects the infrared reflectance spectra of ZnO-based ceramics. • For pure ZnO, the reflectance R (ν) increases in the spectral range with ν> ν LO . • For ZnO:Mn ceramics, the R (ν) rises the spectral range with ν> ν TO . • In magnetic field, plasmon damping rises due to larger electron effective mass. • Magnetic field “decreases” the phonon damping coefficient in ZnO:Mn ceramics.