Tailoring surface phase transition and magnetic behaviors in BiFeO3 via doping engineering

Abstract

The charge-spin interactions in multiferroic materials (e.g., BiFeO3) have attracted enormous attention due to their high potential for next generation information electronics. However, the weak and deficient manipulation of charge-spin coupling notoriously limits their commercial applications. To tailor the spontaneous charge and the spin orientation synergistically in BiFeO3 (BFO), in this report, the 3d element of Mn doping engineering is employed and unveils the variation of surface phase transition and magnetic behaviors by introducing chemical strain. The spontaneous ferroelectric response and the corresponding domain structures, magnetic behaviors and spin dynamics in Mn-doped BFO ceramics have been investigated systematically. Both the surface phase transition and magnetization were enhanced in BFO via Mn doping. The interaction between the spontaneous polarization charge and magnetic spin reorientation in Mn-doped BFO are discussed in detail. Moreover, our extensive electron paramagnetic resonance (EPR) results demonstrate that the 3d dopant plays a paramount role in the surface phase transition, which provides an alternative route to tune the charge-spin interactions in multiferroic materials.

Tailoring the multiferroic behavior in BiFeO3nanostructures by Pb doping

“…This is since the ferroelectricity in BFO originates from the 6s 2 lone pair electrons of Bi 3+ ions due to structural distortion, while the magnetism occurs by Fe-O-Fe superexchange interactions. 6 As an overview, BFO has a disappointingly low spontaneous polarization and saturation magnetization due to the superimposition of a spiral spin structure on BFO that could be attributed to the antiferromagnetic order. 7 In this spiral spin structure, the antiferromagnetic axis rotates through the crystal with an incommensurate long-wavelength period of 62 nm, which cancels the macroscopic magnetization and also inhibits ME coupling.…”

“…Moreover, the substitution for Bi 3+ in BFO can increase distortions in the FeO 6 octahedra and Fe-O-Fe bond angles and, thus, the tetragonality in the crystal structure. 6 The resultant chemical strain from these structural variations can augment the polar displacement of Bi 3+ ions and the 6s 2 lone pair electrons of Bi 3+ ions; as a result increased polarization is expected. 15 In the present paper, we have reported the structural, nanostructural, ferroelectric, magnetic, oxidation state, dielectric and ME properties of multiferroic Bi 1Àx Pb x FeO 3 [x ¼ 0 (BFO), 0.05 (BPFO5), 0.075 (BPFO75) and 0.1 (BPFO10)] nanostructures.…”

Enhanced exchange bias and improved ferromagnetic properties in Permalloy–BiFe0.95Co0.05O3 core–shell nanostructures

“…It has been proven that the magnetic and ferroelectric order can coexist in some unusual perovskite type oxide materials, termed as multiferroics 7 8 9 10 . Among them, BiFeO 3 (BFO) has received the most attention 11 12 13 14 . Since nanostructures might possess excellent properties, it is worth to combine BFO with 1D nanostructures.…”

Ferroelectric Domain Structure and Local Piezoelectric Properties of Lead-Free (Ka0.5Na0.5)NbO3 and BiFeO3-Based Piezoelectric Ceramics

“…Mn-doped BFO samples exhibit a higher volume density of the domain walls than those of undoped ones, suggesting that the Mn ion can effectively reduce the domain size in BFO [ 98 ].…”