Structural, thermal, electrical and magnetic properties of pure and 50% La doped BiFeO3 ceramics

Dielectric anomalies due to grain boundary conduction in chemically substituted BiFeO3

“…The structural parameters obtained from refinement (Table I) match well with the reported values for BFO and doped-BFO. 21,24,27 The decrease in lattice parameters and unit cell volume observed in BNFM in comparison with pure BFO 24 is due to the fact that the effective ionic radii of Nd þ3 (0.983Å )/ Mn þ4 (0.530Å ) are lower than those of Bi þ3 (1.03Å )/Fe þ3 (0.645Å ) in A and B sites. 28,29 The density of the BNFM ceramics was measured using Archimedes principle and it was found to be 7.32 g/cm 3 .…”

“…22,23 Figure 1(a) shows the observed and calculated diffraction patterns of BNFM ceramics at room temperature. Experimental XRD of BNFM shows a very low intense peak at $2h ¼ 28 (marked as *) assigned to the Bi 2 Fe 4 O 9 phase, which can be due to excessive Bi used for compensating volatilization during material synthesis, 24 the Bi 2 Fe 4 O 9 is about 2% compared to the intense peak in BNFM XRD spectra. In these XRD patterns, no extra splitting can be observed in characteristic rhombohedral peaks; thus, it can be concluded that there is no phase transition occurring from rhombohedral to tetragonal or other phases with co-doping of Nd and Mn in A and B sites of BFO.…”

“…The Rietveld refinement of BNFM ceramics has been carried out by considering the rhombohedrally distorted perovskite structure with space group R3c, initial lattice parameters and atomic positions for the simulation were taken from those reported elsewhere. 21,24 The shape of peaks was refined by Pseudo-Voigt function 26 and scale factor, zero shift, specimen displacement, background, transparency, lattice parameters, FWHM, shape parameters, atomic positions, preferred orientation, and anisotropic temperature parameters were varied during refinement process. 23 The diffractometer parameters used for data collection, the crystal structure parameters derived from simulation, and reliability factors are all listed in Table I.…”

Influence of La-doping on structure and magnetic behaviors in BiFeO3

“…The experimental and calculated XRD patterns of Bi 1-x La x FeO 3 are shown in Fig.1 (1 1 1) planes leading to the G-type antiferromagnetic ordering [22,23]. Compared to BFO, the peaks in XRD pattern are found to shift to higher angle with the increasing amount of La dopant.…”

Synthesis, Structural, Electrical and Thermal Properties of ScFeO<sub>3</sub> Ceramic

“…Here ( figure 6) the dissipation factor shows the same trend as that of dielectric constant with temperature. As the frequency increases, dissipation factor decreases indicating low ac dielectric losses at higher frequency [21]. Thus with the increase in frequency the atomic/ionic and electronic contribution becomes dominant and space charge contribution gradually diminishes resulting in decrease of dissipation factor with increase in frequency [22].…”