Evidence of improved ferroelectric phase stabilization in Nd and Sc co-substituted BiFeO3

Abstract

Polycrystalline BiFeO3 and Bi0.9Nd0.1Fe1-xScxO3 (x = 0, 0.05 and 0.10) multiferroic compounds were prepared using conventional solid-state route. X-ray diffraction studies and Raman measurements indicated that the compounds were crystallized in rhombohedral structure with R3c space group. Weak ferromagnetism was induced due to the suppression of canted spin structure in the substituted compounds. Both remnant magnetization (Mr) and coercive field (Hc) were enhanced in Nd and Sc substituted compounds. Further, Néel temperature TN was decreased from 644 K for BiFeO3 to 550 K for Bi0.9Nd0.1Fe0.9Sc0.1O3 compound due to weakening of magnetic exchange interactions between B-site cations in the 2 substituted compounds. Enhanced and nearly well saturated electrical polarizations were observed in Sc substituted compounds which is attributed to the strengthening of covalent hybridization between Bi and O ions and reduction in oxygen vacancies. The remnant polarization was enhanced to 12.5 µC/cm 2 in Bi0.9Nd0.1Fe0.9Sc0.1O3 compound. Impedance studies reveal that insulating character of substituted compounds is enhanced and electrical relaxations are of non-Debye type.

Microstructures, magnetic, and dielectric properties of Ba‐doped BiFeO3 nanoparticles synthesized via molten salt route

“…The group theory predicts that there are 13 active Raman modes in the BFO with R3c space group, which can be described as: Γ = 4 A 1 + 9 E . Among them, the low frequency Roman modes (below 170 cm −1 ) are associated with Bi atom, while those at median frequencies (150‐270 cm −1 ) are responsible for Fe atom . At room temperature, the Raman spectrum of the nondoped BFO nanoparticles and the fitted curves is depicted in Figure A.…”

Study the influence of Nd and Co/Cr co-substitutions on structural, electrical and magnetic properties of BiFeO 3 nanoparticles

“…In this manner, Rao at el. prepared Nd-Sc co-substituted BFO ceramic and found phase stabilization with remarkably enhanced multiferroic properties [27]. Khomchenko et al studied the Bi 1-x Nd x Fe 1-x Mn x O 3 multiferroic system and revealed structural phase transformation from polar state to non-polar one with increasing 'x', but got enhanced magnetization [28].…”

Improved magnetization and reduced leakage current in Sm and Sc co-substituted BiFeO3

“…It has been observed that the substitution of Sc at the Fe-site of BFO enhances the insulating character by reducing the leakage current. 10,11 Also, it is reported that rare earth substitution at Bi-site enhances the multiferroic properties and reduces the leakage currents. 11,12 In addition to the improved properties, the substitution distorts the crystal structure and transforms to another structure.…”

“…10,11 Also, it is reported that rare earth substitution at Bi-site enhances the multiferroic properties and reduces the leakage currents. 11,12 In addition to the improved properties, the substitution distorts the crystal structure and transforms to another structure. A structural transition from rhombohedral to an orthorhombic structure is observed for 0.10 < x < 0.15 in the Bi 1-x Eu x FeO 3 compound.…”

“…The enhanced coercive field in the BSFSO compound may be due to the change in structural anisotropy in the compound. 11 The improved H c is explained using the formula…”