Investigation on the optical, electrical, dielectric, and magnetic properties of (1-x)La_(0.7)Ca_(0.3)MnO_3/xCoFe_2O_4 nanocomposites

摘要

(1-x)La0.7Ca0.3MnO3/xCoFe(2)O(4) (x=0, 0.1, 0.3) nanocomposites are fabricated by glycine-nitrate method. XRD patterns and FTIR spectra confirm the phase formation of the nanocomposite. FESEM images divulge a reduction in the average particle size with enhanced incorporation of CoFe2O4. The band gap increases moderately followed by a blue shift in UV-Vis absorption peaks. Frequency-dependent impedance and dielectric properties are investigated at and above the room temperature. The impedance of the system gets enhanced while the conductivity reduces accordingly. Nyquist plot of impedance displays the contribution of diverse nanostructures on the electrical property using R(Q(g)R(g))(Q(gb)R(gb)) circuit. Two types of conduction mechanism are observed in the studied system. The conduction in the low frequency regime is associated with correlated barrier hopping type conduction mechanism and in the high frequency regime is associated with overlapped large polaron tunneling conduction mechanism. The dielectric constant and tangent loss both are reduced on the incorporation of CoFe2O4. Comparatively low tangent loss value for x=0.3 reflects suitability in high-frequency device applications. The saturation magnetization M-s and squareness ratio S is also high for x=0.3 that is valuable for possible use of the (1-x)La0.7Ca0.3MnO3/xCoFe(2)O(4) nanocomposites in memory devices.