Magnetic, Dielectric, Magnetoelectric properties and impedance spectroscopy of Multiferroic Bi_(1-x)Nd_xFe_(1-y)Co_yO_3 (x=0, 0.10, 0.15, 0.20, y=0, 0.10) nanoceramics

摘要

Single phase multiferroic Bi_(1-x)Nd_xFe_(1-y)Co_yO_3 (x=0, 0.10, 0.15, 0.20; y = 0, 0.10) nanoparticles (average particle size 20-80 nm) were synthesized by novel chemical sol-gel route. The detailed microstructural analysis has been performed using HRXRD, HRTEM and FESEM techniques. The Rietveld refinement of the XRD data reveals that the samples are well crystalline with distorted rhombohedral structure having R3c space group without having any iron rich impurity phases. A noticeably large value of dielectric constant (880) and low tan δ loss (0.04) are observed for the sample Bi_(0.9)Nd_(0.1)Fe_(0.9)Co_(0.1)O_3 at 100 Hz at room temperature. An anomaly near the Neel temperature in dielectric measurement has been observed for the samples with x = 0.10 and y = 0.0, 0.10. This anomaly has also been found in temperature dependent dielectric loss curve. A spectacular enhancement of M_s (7.26 emu/gm) and coercivity H_c (1.75 T) has been observed for Bi_(0.9)Nd_(0.1)Fe_(0.9)Co_(0.1)O_3 nanoceramics revealing ferromagnetic ordering at the ground state (5 K). We have also observed well saturated P-E Hystersis loops with a remanent polarization (P_r) of 0.2 μC/ cm~2 and coercive field E_c of 5 kV/cm for Bi_(0.9)Nd_(0.1)Fe_(0.9)Co_(0.1)O_3 nanoceramics.