Investigation of magneto-electric properties of La0.85Nd0.15Fe0.9Ti0.1O3

Solid state reaction route was employed to synthesize nanoparticles of undoped LaFeO3 (LFO) and Nd3+-Ti4+ codoped LFO (La0.85Nd0.15Fe0.9Ti0.1O3, LNFTO) therein was considered to modulate its magneto-dielectric properties. The prepared samples were annealed at 1400 degrees C for 4 h to get the desired crystallographic phase. From the recorded X-ray diffractograms (XRD) it was confirmed that both dopants, Nd3+ and Ti4+ successfully entered in LFO lattice with some deviations from ideal perovskite lattice where the FeO6 octahedron is distorted. The XRD data were also used for extracting cell parameters using Rietveld analysis. Raman spectroscopic data of LFO and LNFTO were recorded at room temperature (RT) to identify the presence of impurities, if any. Magnetization (M) vs applied field (H) of LNFTO recorded at 300, 5 and 2 K show the presence of magnetic ordering with fruitful modulations in shape of curve and value of magnetization in co-doped sample compared to those of LFO. Analysis of M vs temperature (T) curve indicates that co-doped sample of LNFTO is in mixed phase of ferromagnetism and antiferromagnetism. Frequency-dependent dielectric constant (epsilon'), dielectric loss tangent (tan delta), ac conductivity (sigma'), z parameters of LNFTO were measured at different temperatures (in the range of 25 degrees C to 225 degrees C). epsilon' value of LNFTO increases and tan delta decreases compared to undoped LFO. On the other hand, variation of s' with frequency of LNFTO decreases, and accordingly resistivity increases. Variation of polarization (P) with electric field (E) of LNFTO recorded at RT indicates that P-E loops of LNFTO are improved compared to that of LFO. Leakage current density (J) vs electric field (E) characterisation shows that leakage current reduces in LNFTO. Nature of the J-E curve depicts that the resistive behavior of sample LNFTO is not linear, which confirms the presence of charge storage phenomena in the samples.