相关论文: Structural phase transitions in perovskite BaCeO3 …

The incompatibility of partial d occupation on the perovskite B-site with the standard charge transfer mechanism for ferroelectricity has been a central paradigm in multiferroics research. Nevertheless, it was recently shown by density…

Phase change materials (PCMs) that exhibit volatile resistive switching are promising for emulating neuronal oscillators. Charge transfer insulators, such as ReNiO3 (where Re represents rare earth metals like Pr, Nd, Sm, Eu...), form a…

We have carried out the powder x-ray diffraction and dielectric studies on multiferroic particulate composite xNi0.9Zn0.1Fe2O4/(1-x)PbZr0.52Ti0.48O3 with x=0.15, 0.30, 0.45, 0.60, 0.75 and 0.90 to explore the structural and ferroelectric…

Earths lower mantle extending from 670 to 2,990 km deep is predominantly composed of a perovskite-type (Mg,Fe)SiO3 phase1,2. The perovskite phase undergoes a structural phase transition to a post-perovskite phase responsible for D" layer…

We report the nonlinear dielectric properties of three triple-perovskite ruthenates: Ba$_3$CoRu$_2$O$_9$, Ba$_3$BiRu$_2$O$_9$, and Sr$_3$CaRu$_2$O$_9$. These compounds exhibit notable correlations among their spin, charge, lattice, and…

The (H,T)-phase diagram of the multiferroic perovskite TbMnO$_3$ was studied by high-resolution thermal expansion $\alpha(T)$ and magnetostriction $\Delta L(H)/L$ measurements. Below $T_{N}\simeq 42$ K, TbMnO$_3$ shows antiferromagnetic…

We have investigated the structural phase transitions of the transition metal oxide perovskites SrTiO$_{3}$, LaAlO$_{3}$ and LaTiO$_{3}$ using the screened hybrid density functional of Heyd, Scuseria and Ernzerhof (HSE06). We show that…

We performed factor-group analysis of all phonons in possible monoclinic C2/c and C2 structures of BiMnO3 and compared it with our experimental infrared and Raman spectra. We conclude that the crystal structure is centrosymmetric C2/c in…

The planar hexagonal phase of ZnO, known as h-ZnO, g-ZnO, {\alpha}-ZnO, the Bk structure, the 5-5 phase, the {\alpha}-BN phase, etc., has P63/mmc symmetry and is implicated in ferroelectric switching mechanisms for wurtzite-ZnO. It is…

Temperature dependent crystal structures of the quasi-one-dimensional ladder material BaFe2Se3 are examined. Combining the optical second harmonic generation (SHG) experiments and neutron diffraction measurements, we elucidate the crystal…

A novel stable crystallographic structure is discovered in a variety of ABO3, ABF3 and A2O3 compounds (including materials of geological relevance, prototypes of multiferroics, exhibiting strong spin-orbit effects, etc...), via the use of…

KCrF3 represents another prototypical orbital-ordered perovskite, where Cr2+ possesses the same electronic configuration of 3d4 as that of strongly Jahn-Teller distorted Mn3+ in many CMR manganites. The crystal and magnetic structures of…

The structural changes of TlCoCl$_3$ around phase IV (68 K $<T<$ 75 K) were studied by single-crystal neutron diffraction measurement. The present investigation revealed that a small but definite Bragg peak at (${1/6} {1/6} 2$) appeared…

We use the density functional perturbation theory to determine for the first time the pressure evolution of the Raman intensities for a mineral, the two high-pressure structures of MgSiO3 perovskite and post-perovskite. At high pressures,…

Among the phases of SiO2 are alpha and beta cristobalites, which have a long and somewhat controversial history of proposed structural assignments and phase-transition mechanisms. Recently, Zhang and Scott found new indications that the…

The hybrid perovskites [CH$_3$NH$_3$]Co$_x$Ni$_{x-1}$(HCOO)$_3$ with $x$ = 0, 0.25, 0.5, 0.75 and 1.0 possess multiple phase transitions including incommensurate structures. [CH$_3$NH$_3$]Ni(HCOO)$_3$ has also been found to have a proper…

We report the time dependent response of electrical resistivity in the non-magnetic perovskite oxide NdNiO$_3$ in its phase separated state and provide a physical explanation of the observations. We also model the system and do an accurate…

In this paper, we present the study of the structural, mechanical, magneto-electronic and thermodynamic properties of the perovskite KBeO$_3$. The calculations were performed by the full potential augmented plane wave method, implemented in…

Millimeter sized single crystals of Mo3Sb7 are grown using the self-flux technique and a thorough characterization of their structural, magnetic, thermal and transport properties is reported. The structure parameters for the…

Barium titanate (BaTiO$_3$) is a prototypical ferroelectric perovskite that undergoes the rhombohedral-orthorhombic-tetragonal-cubic phase transitions as the temperature increases. In this work, we develop a classical interatomic potential…