Structural, morphological, electrical and dielectric properties of Mn doped CeO2

Present study reports the structural and dielectric properties of Ce1-xMnxO2 (0 ≤ x ≤ 0.15) compounds synthesized by solid state reaction method. X-ray diffraction and Raman measurements confirm the formation of cubic phase corresponding to Fm3m space group for all these compositions investigated. The transition metal Mn ions exhibit multivalency nature in oxides and doping these ions at Ce sites in CeO2 which is also known to exist in 3+ and 4+ valency state is expected to modify the physical properties. The crystallite size was found to decrease with Mn concentration up to 7%, however, it increases at higher Mn concentration i.e., x = 0.15 which is also confirmed by the images from Scanning Electron Microscope. Raman study reveals red shift in peaks at ∼462.9 cm−1 and ∼572.9 cm−1 upto x = 0.07, whereas the blue shift was observed from these peaks for x = 0.15. The electrical resistivity measured as a function of temperature (200 K-380 K) indicates an increase in resistivity with Mn doping. Furthermore, the dielectric measurements performed with varying frequency as well as temperature shows an enhancement in dielectric constant and decrease in the dielectric loss with Mn concentration.