Multiferroic properties of Aurivillius phase Bi₆Fe_2−xCo_xTi₃O₁₈ thin films prepared by a chemical solution deposition route

Multiferroic and dielectric properties of Bi4LaTi3FeO15 ceramics

“…Therefore, attempting to synthesize room temperature multiferroic materials is a challenging task of materials science. Doping magnetic species into ferroelectric matrices is one of the most effective ways to obtain room temperature multiferroics, and thus has received much attention in the past few years [4][5][6][7][8][9][10][11][12][13]. Ferromagnetism was successfully introduced in the ferroelectric BaTiO 3 material by Fe doping, however, its ferroelectricity was suppressed simultaneously due to the decreased tetragonal distortion and the enhanced leakage current [4].…”

Cobalt-Substituted Seven-Layer Aurivillius Bi8Fe4Ti3O24 Ceramics: Enhanced Ferromagnetism and Ferroelectricity

“…Obviously, the FM properties of such sevenlayered BFCT ceramics were significantly enhanced by the Co partial substitution, and 2Mr reached 0.04 emu/g, 0.30 emu/g, 0.35 emu/g and 0.69 emu/g for x = 0.1, 0.2, 0.3 and 0.4 samples, respectively. This enhancement could be explained by the possible superexchange among oxygen-connected Fe and Co ions, and the structure-modulated spin canting (the canting angle and the length between coupled ions) from the titling of adjacent Fe-O and Co-O octahedrals [16][17][18]. Furthermore, Figure 3c …”

“…Its remanent magnetization (2Mr) was improved to 7.8 memu/g, due to a possible existence of superexchange among oxygen-connected Fe and Co ions and the realigned spin structures caused by the substitution [16]. Following this work of using the Co substitution strategy, most recent investigations on Bi6FeCrTi3O18 [13], Bi6Fe2−xCoxTi3O18 [17] (n = 5) and Bi7Fe3−xNixTi3O21 [18] (n = 6) also revealed an enhanced FM performance at or above room temperature. Remarkably, Wang et al reported a plausible intrinsic magnetoelectric (ME) coupling in a five-layered Aurivillius ceramic, SrBi5Fe0.5Co0.5Ti4O18, even at a high temperature of 373 K, surpassing almost all single-phase multiferroic materials currently under investigation [19].…”

“…Obviously, the FM properties of such seven-layered BFCT ceramics were significantly enhanced by the Co partial substitution, and 2Mr reached 0.04 emu/g, 0.30 emu/g, 0.35 emu/g and 0.69 emu/g for x = 0.1, 0.2, 0.3 and 0.4 samples, respectively. This enhancement could be explained by the possible superexchange among oxygen-connected Fe and Co ions, and the structure-modulated spin canting (the canting angle and the length between coupled ions) from the titling of adjacent Fe-O and Co-O octahedrals [16][17][18]. Furthermore, Figure 3c reveals the ZFC-FC measurements of samples with x = 0.1, 0.2 0.3 and 0.4, and the curves indicate the magnetic Curie temperatures (here also simplified as T N ) of such ceramics, the ferromagnetism-to-paramagnetism transition temperatures (marked as the peak of dM/dT curves), were about 776 K, 764 K, 762 K and 750 K, respectively, which are much higher than RT.…”

A study of the temperature dependence of the local ferroelectric properties of c-axis oriented Bi6Ti3Fe2O18 Aurivillius phase thin films: Illustrating the potential of a novel lead-free perovskite material for high density memory applications

“…3,14 To date, an extensively studied and scientifically interesting family of bismuth-based piezoelectrics is the bismuth layer-structured ferroelectric (BLSF) family in the Aurivillius phase. [15][16][17][18] Aurivillius phase materials are naturally 2-D nanostructured, consisting of (Bi 2 O 2 ) 2+ blocks interleaved with alternating nABO 3 perovskite units (where n ranges from 2-9), described by the general formula Bi 2 O 2 (A n−1 B n O 3n+1 ), where A represents differing cations with valence states ranging from +1 to +3 such as monovalent Na + , K + , divalent Ca 2+ , Mg 2+ , Sr 2+ , Pb 2+ , Ba 2+ and trivalent Zr 3+ , Yt 3+ etc. B represents cations with valence states ranging from +3 to +5 such as Fe, Mn, Ti, Nb etc.…”