相关论文: Origin of the multiferroic spiral spin-order in th…
We report an interesting reentrant metallic resistivity pattern beyond a characteristic temperature T* which is higher than other such characteristic transition temperatures like T(c)(Curie point), T(N) (Neel point), T(CO) (charge order…
Multiferroics where at least two primary ferroic orders are present and coupled in a single system constitute an important class of materials. They attracted special consideration as they present both intriguing fundamental physics problems…
The double-perovskite A$_2$BB'O$_6$ with heavy transition metal ions on the ordered B' sites is an important family of compounds to study the interplay between electron correlation and spin-orbit coupling (SOC). Here we prepared…
By combining neutron four-circle diffraction and polarized neutron diffraction techniques we have determined the complex spin structures of a multiferroic, YMn2O5, that exhibits two ferroelectric phases at low temperatures. The obtained…
Structural, magnetic and electric properties of a metal-ordered perovskite YBaMn2O6 have been studied by means of powder X-ray diffraction, DSC, magnetic susceptibility, and electric resistivity. It is found that this material undergoes a…
We study a two-dimensional effective orbital superexchange model derived for strongly correlated e_g electrons coupled to t_{2g} core spins in layered manganites. One finds that the ferromagnetic and antiferromagnetic correlations closely…
We analyzed the possible magnetic and orbital orderings of double perovskites, using a simple extension of the double exchange model well suited for these compounds. Orbital ordering is favored by the on site repulsion at the Fe ions. We…
The three dimensional perovskite manganites in the range of hole-doping $x > 0.5$ are studied in detail using a double exchange model with degenerate $e_g$ orbitals including intra- and inter-orbital correlations and near-neighbour Coulomb…
The spin structure of a Mn triple layer grown pseudomorphically on surfaces is studied using spin-polarized scanning tunneling microscopy (SP-STM) and density functional theory (DFT). In SP-STM images a c$(4 \times 2)$ super structure is…
Spin-nematic and spin-smectic phases have been reported in magnetic materials, which break rotational symmetry while preserving translational symmetry along certain directions. However, until now the analogy to liquid crystals remained…
We report the comprehensive experimental results identifying the magnetic spin ordering and the magnetization dynamics of a double perovskite Pr2CoFeO6 by employing the (dc and ac) magnetization, powder neutron diffraction (NPD) and X-ray…
The magnetism of double perovskites is a complex phenomenon, determined from intra- or interatomic magnetic moment interactions, and strongly influenced by geometry. We take advantage of the complementary length and time scales of the muon…
We consider a lattice model of itinerant electrons coupled to an array of localized classical Heisenberg spins. The nature of the ground state ordered magnetic phases that result from the indirect spin-spin coupling mediated by the…
We study the existence of incommensurate phases in the phase diagram of the two orbital double exchange model coupled with Jahn-Teller phonons and with superexchange interactions. In agreement with experimental results, we find that undoped…
First-principles calculations have been performed for different collinear magnetic orderings in orthorhombic manganites, such as HoMnO3, TbMnO3 and YMnO3, showing large GdFeO3-like distortions. Our results suggest that the AFM-E type…
We put forward double perovskites of the R$_2$NiMnO$_6$ family (with $R$ a rare-earth atom) as a new class of multiferroics on the basis of {\it ab initio} density functional calculations. We show that changing $R$ from La to Y drives the…
The layered perovskite YBaCuFeO5 (YBCFO) is considered one of the best candidates to high-temperature chiral multiferroics with strong magnetoelectric coupling. In RBaCuFeO5 perovskites (R: rare-earth or Y) A-site cations are fully ordered…
We study how strain affects orbital ordering and magnetism at the interface between SrMnO$_3$ and LaMnO$_3$ from density-functional calculations and interpret the basic results in terms of a three-site Mn-O-Mn model. Magnetic interaction…
It is shown that the time-reversal symmetry is broken during the phase transition causing orbital ordering in a crystal with Jahn-Teller (J-T) ions. This means that such phase transitions are magnetic ones. As an example we have considered…
In a recent publication (S. Dong et al., Phys. Rev. Lett.103, 127201 (2009)), two (related) mechanisms were proposed to understand the intrinsic exchange bias present in oxides heterostructures involving G-type antiferromagnetic…