Room-temperature magnetic studies of La-modified BiFeO3 ceramic

Magneto-electric properties of Nd substituted BiFeO3 polycrystalline samples

“…The structure and properties of the bulk single crystal form have been extensively studied. But, there are still some difficulties which have limited its development like; it is hard to get single phase compound with high electrical resistivity and ferromagnetism [15]. It has been found that the magnetism and ferroelectricity in BFO can be improved by substituting A-site ion with rare-earth [15][16][17][18] or alkaline-earth [19,20] ions or replacing B-site ion with transition-metal and rare-earth ones [21][22][23][24].…”

Studies of La- and Pr-driven reverse distortion of FeO6 octahedral structure, magnetic properties and hyperfine interaction of BiFeO3 powder

“…The EDS and XRD results conrm that the increasing crystal parameters of the samples provide evidence for the substitution of Bi ions with La and Pr, which results from a slightly bigger ionic radius of La 3+ (1.032Å) and a smaller ionic radius of Pr 3+ (0.99Å) when compared with the ionic radius of Bi 3+ (1.030Å). [27][28][29] As shown in Fig. 1b, the double split peaks corresponding to the (104) and (110) planes in BLPFO powders are distinctly observed, and they have a slight shi to the le.…”

“…The lattice distortion enhances the DM interaction and results in the spin cycloid destruction, 46 which modies the Fe-O bond lengths and Fe-O-Fe bond angles, in particular those in the Fe local environment. 28,44 Pokatilov et al studied the local states of iron ions in multiferroic Bi 1Àx La x FeO 3 and claimed that the substitution of La 3+ ions with outer electron shell 5d 1 6s 2 for Bi 3+ ions having an outer electron shell 6s 2 6p 3 introduces one d electron in the samples. 47 On the basis of this conclusion, the enhancement in hyperne magnetic eld H of the samples can be explained by the fact that the polarization of the s electrons in the inner closed shells enhances the Fermi contact interaction, which is caused by the exchange interaction between the s electrons and the 3d electrons of the iron ions.…”

Improved multiferroic properties in (1−x)BiFeO3–xBaTi0.95(Yb0.5Nb0.5)0.05O3 system (0≤x≤0.3)

“…In addition, the two different values of quadrupole shift were connected with different trigonal distortions of the octahedral environment of iron sites as concluded by De Sitter et al[31]. In fact, this is linked to a non-collinear magnetic structure of the cycloid type as confirmed by neutron diffraction and Mössbauer spectroscopy studies performed by Sosnowska et al[32,33].For doped ceramics (x = 0.1, 0.2 and 0.3), the best fits were performed by adding a third sextets that could be assigned to a change of the magnetic nearest neighbors of Fe 3+[34][35], as substituted by Yb 3+ /Nb 5+ /Ti 4+ leading to a distortion of FeO 6 octahedral origin of structural transition. This could lead to modulation spin structure which contributed to the improvement of magnetization.According to table 2, The isomer shift of all the sextets was around 0.38 -0.42 mms -1 .…”