Spiral magnetic ordering in bismuth ferrite

Structural and magnetic properties of isovalently substituted multiferroic BiFeO3: Insights from Raman spectroscopy

“…9 The magnetic moments of the Fe 3+ ions are arranged in a cycloidal fashion of periodicity 620Å along [110], superimposed on a slightly canted G-type antiferromagnetic order. 10 In the absence of cycloidal spin order, as is achieved both in BiFeO 3 thin films 1 and isovalently substituted BiFe 1−x Mn x O 3 , 7 linear magnetoelectric effects in the noncentrosymmetric phases of BiFeO 3 related ceramics become symmetry allowed and activate by a coupling between the A-site ferroelectric translation and the B-site magnetization via the antiferrodistortive a − a − a − tilt of the oxygen octahedra. 11 Although the linear magnetoelectric effect is symmetry forbidden on a macroscopic scale, the DzyaloshinskiiMoriya mechanism can still be used locally in bulk BiFeO 3 to achieve an electric switching of the spin cycloid.…”

Magnetoelectric Ordering of BiFeO3 from the Perspective of Crystal Chemistry

“…At the same time, bismuth ferrite has a substantial disadvantage. It was stated [5][6][7] that the non-collinear magnetic structure of bismuth ferrite comprising a modulated spin structure with a large period prevents from emerging of the linear magnetoelectric effect and spontaneous magnetization. One of the ways of suppressing the modulated spin structure is the application of a strong magnetic field [8][9][10].…”

“…The experimental studies of BiFeO 3 [18][19][20] established that the temperature increase produced consecutive structural phase transitions from the ferroelectric -phase (rhombohedral space group R3c with a = 5.6 Å, c = 13.9 Å and γ=120) [5,[21][22][23][24][25][26][27]] to two paraelectric phases. First, the process leads to the orthorhombic ß-phase [19] (space group Pbnm with a = 5.613 Å, b = 5.647 Å, and c = 7.971 Å) between 820º C and 830º C and then, in the range 925-933º C, to the cubic -phase [18] (space group m Pm3 with a = 3.992 Å), which decomposes above 960º C. The transition to the cubic phase is accompanied by the insulator-metal transition [18].…”

Interface induced out-of-plane magnetic anisotropy in magnetoelectric BiFeO3-BaTiO3 superlattices

“…16 It is well known that bulk BiFeO 3 is a G-type antiferromagnet possessing a cycloidal spin structure with a period of 62 nm. 17 The magnetic moment gradually rotates in the plane determined by the propagation direction of the cycloid [1][2][3][4][5][6][7][8][9][10] and the polarization direction [111], which is the principal axis of the electric field gradient (EFG) tensor (Fig. 1).…”