Electronic and Magnetic Field Dependent Dielectric Properties of Zn0.95Fe0.05O

摘要

We report a magneto-dielectric effect in Zn0.95Fe0.05O, which was synthesized by the microwave-assisted combustion method. The x-ray diffraction (XRD) pattern of Zn0.95Fe0.05O shows the shift in peaks towards lower theta values in comparison to the XRD pattern of ZnO. Rietveld analysis of XRD data shows the presence of 99.29% of Zn0.95Fe0.05O along with 0.71% ZnFe2O4 in Fe doped ZnO. Infrared spectroscopic studies show the shift in absorption peak towards lower wavenumber with Fe doping at Zn sites in ZnO. Soft x-ray absorption spectroscopy studies show the mixed valence states of Fe (Fe+2 and Fe+3). Magnetic properties show paramagnetic behaviour of Zn0.95Fe0.05O at room temperature. The magneto-dielectric effect is originated in Zn0.95Fe0.05O due to the decrease in space polarization effect in the presence of Fe+2 at the Zn site in a magnetic field. The dielectric constant epsilon(r) is found to be 4.09 x 10(5) in 1Hz and 11.65 in 1 MHz frequency in the absence of a magnetic field for Zn0.95Fe0.05O. The dielectric constant epsilon(r) is found to be 2.88 x 10(5) in 1 Hz and 10.37 in 1 MHz frequency in the 500 Gauss magnetic field for Zn0.95Fe0.05O. Magnetic field sensitivity is found as similar to 16% in the 15 kG magnetic field and 30 MHz frequency for Zn0.95Fe0.05O.