Ferromagnetism in multiferroicBiFeO3films: A first-principles-based study

Influence of epitaxial strain on clustering of iron inPb(Fe1/2Nb1/2)O3Prosandeev1, Raevski2, Raevskaya3 et al. 2015Phys. Rev. B19150View full textAdd to dashboardCite

“…The self-consistent calculations of the parameter U responsible for the d − d Coulomb interaction on Fe ions in BiFeO 3 gave U equal to 3.8 eV 36 , and, in FeO, it is equal to 4.3 eV 37 . Note that the dependence of the stability of different chemical configurations on U in PFN has been already studied earlier 11 .…”

Exploiting interfacial and size effects to construct oxide superlattices with robust and tunable magnetoelectric properties at room temperature

“…For example, the largest M values at the lowest T shown (200 K) correspond to the SLs with thickest BMO layers (see results for n/m > 1.25). In such cases we obtain M (200 K) ≈ 0.4 µ B per transition metal atom (µ B /tma in the following), which is about 40 times of BFO thin film; unfortunately, the magnetization decays very rapidly when we approach T room , reaching values of about 0.02 µ B /tma that are comparable to the magnitude of the canted moment in BFO thin films [5][6][7]. In contrast, we find cases in which M (T ) is constant in the T range considered, presenting sizable values between ≃ 0.1 µ B /tma and ≃ 0.3 µ B /tma at T room , which is about one order of magnitude larger than that of BFO films.…”

“…4a 's MEM phase, we know that the G-AFM order parameter lies in a plane perpendicular to the polarization direction (see Fig. 4b-d), and such a plane changes when an electric field is used to make P switch between equivalent polar states [7,38,39]. In our SLs, the polarization should be easily switchable by 109…”

“…Today, the most robust room-temperature multiferroics are materials like BiFeO 3 (BFO) [4], where magnetism is associated with the Fe 3+ cations located at the B-site of the lattice, while ferroelectricity is driven by the offcentering of the A-site Bi 3+ cations. The simple ABO 3 perovskites displaying roomtemperature multiferroism tend to have an antiferromagnetic (AFM) structure; in some cases, the AFM order is modulated, in others it presents a spin canting that gives rise to a small magnetic moment (e.g., about 0.01 µ B per Fe cation in AFM thin films of BFO) [5][6][7]. Large magnetization values are unheard of in this context, for fundamental reasons: MEM perovskite oxides are insulators in which the dominant magnetic interaction is super-exchange.…”

Terahertz Dielectric Response and Coupled Dynamics of Ferroelectrics and Multiferroics From Effective Hamiltonian Simulations

“…Antiferrodistortive (AFD) motions 30,34 and magnetic degrees of freedom 31,35 were also incorporated in some effective Hamiltonians. For instance, in the multiferroic BiFeO 3 material, the resulting effective Hamiltonian has a total energy that can be written as a sum of two main terms 31,35,36 :…”