Ferroelectric order stability in theBi1−xPbxFeO3solid solution

Abstract

Ferroelectric properties of Bi 1−x Pb x FeO 3 , through a structural approach, by structural Rietveld refinement and x-ray diffraction versus temperature have been carried out. This study allows us to draw a phase diagram for the system Bi 1−x Pb x FeO 3 . Although lead atom gets a lone pair and is commonly understood as having a "ferroelectric" character, we report in this paper that adding of lead atom in the Bi subsystem of BiFeO 3 , destroys the long-range FE order induced by Bi lone pairs on contrary, and progressively breaks the ferroelectric ordering up to the point where the structure becomes cubic on average. The decreasing of T C with increasing Pb content also confirms that adding of Pb atoms destabilizes the ferroelectric rhombohedral order and stabilizes the cubic phase via a complex texture of mixed phases, occurring at a local scale.

Rare earth (La) and metal ion (Pb) substitution induced structural and multiferroic properties of bismuth ferrite

“…The diffraction peaks change in both intensity and 2 value with different doping as a result of change in crystal structure. Pristine BiFeO 3 possesses rhombohedral structure with space group R3c and matches well with earlier published reports [19][20][21][22][23][24][25][26][27][28][29].…”

“…Further, the difference in the charge and ionic radii of Bi 3+ and Pb 2+ can also direct to topological changes in the oxygen octahedra. One recent study on Pb substitution reported a structural phase transition reducing the rhombohedral distortion and progressively breaking the ferroelectric order [23].…”

Properties of Bi0.8Ln0.2FeO3 (Ln=La, Gd, Ho) multiferroic ceramics

“…As can be seen, the calculated XRD patterns coincide well with the measured XRD patterns with small R values (R wp 5.64%, R p 3.79%). Generally, to calculate the values of c pc /a pc , the rhombohedral cell parameters are expressed in the pseudocubic cell: a pc = a hex / 2 and c pc = c hex /(2 3 ) [14,15], and the ratio c pc /a pc increases from 1.0115 for bulk BLFO to 1.0136 for BHFO.…”

Effect of Pb doping on multiphase coexistence and magneto-electric properties of bismuth ferrite

“…The crystal structure and multiferroic properties of BiFeO 3 can be modified by introduce a doping. Chaigneau et al [4] reported that Pb content and temperature affect the transformation structural of BiFeO 3 from rhombohedral to pseudocubic system, while influence of Pb doping on the multiferroic properties was reported by Zhang et al [5].…”