ELECTRICAL AND IMPEDANCE PROPERTIES OF IRON DEFICIENT M-TYPE Ni-Mn DOPED BaFe12O19 HEXAGONAL FERRITES

The present study investigated the AC conductivity, complex impedance and dielectric modulus of Ni-Mn doped M-type Barium Hexaferrite with the chemical composition of BaNixMnxFe12-2xO19 (BNMFO) (x=0.0-0.5) prepared by a simple hydrothermal method followed by calcination at 950oC for 5 hours. The frequency dependence of ac conductivity was analyzed by power law for a frequency range from 100Hz to 5MHz. The measured ac conductivity values varied in the range of 4-6×10-4 S/cm at the frequency 4MHz. The dc conductivity values for the contents x=0.0-0.5 were in ranging from 0.9-1×10-6 S/cm. The dielectric relaxation and electrical conduction mechanisms were studied using impedance spectroscopy and dielectric modulus. The contribution of grain and grain boundaries in the electrical conduction process of BNMFO has been discussed effectively with the help of Cole-Cole plots.