相关论文: Modulated, three-directional, and polar structural…

The local structure of high pressure BaTiO$_3$ has been interrogated by neutron total scattering methods, up to pressures of 4.18 GPa at ambient temperature. Competitive refinements of cubic, tetragonal and rhombohedral distortion modes…

Structural, electronic and magnetic properties of Ti$_5$O$_9$ have been studied by \textit{ab initio} methods in low-, intermediate- and high-temperature phases. We have found the charge and orbital order in all three phases to be…

Ferroelectrics are characterized by domain structures as are other ferroics. At the nanoscale though, ferroelectrics may exhibit non-trivial or exotic polarization configurations under proper electrostatic and elastic conditions. These…

A detailed temperature and pressure investigation on BiGdO$_{3}$ is carried out by means of dielectric constant, piezoelectric current, polarization-electric field loop, Raman scattering and x-ray diffraction measurements. Temperature…

The pressure-induced transition of vanadium from BCC to rhombohedral structures is unique and intriguing among transition metals. In this work, the stability of these phases is revisited by using density functional theory. At finite…

The nanostructural evolution of the strain-induced structural phase transition in BiFeO3 is examined. Using high-resolution X-ray diffraction and scanning-probe microscopy-based studies we have uniquely identified and examined the numerous…

Highly-strained BiFeO3 exhibits a "tetragonal-like, monoclinic" crystal structure found only in epitaxial films (with an out-of-plane lattice parameter exceeding the in-plane value by >20%). Previous work has shown that this phase is…

The magnetic properties of single-crystal EuTiO3 are suggestive of nanoscale disorder below its cubic-tetragonal phase transition. We demonstrate that electric field cooling acts to restore monocrystallinity, thus confirming that emergent…

Ferroelectric materials embedded with dielectric inclusions offer a unique platform for exploring novel topological polar textures. Using first-principles-based atomistic simulations, we investigate the polarization behavior of a BaTiO$_3$…

A correlation between the crystal structure and magnetic properties of system (1-x)BiFeO$_3$-(x)BaTiO$_3$ with compounds across the morphotropic phase boundary was studied using X-ray and neutron diffraction, magnetometry, and Mossbauer…

Results of first principles augmented spherical wave electronic structure calculations for niobium dioxide are presented. Both metallic rutile and insulating low-temperature NbO2, which crystallizes in a distorted rutile structure, are…

Despite similar chemical compositions, LiOsO$_3$ and NaOsO$_3$ exhibit remarkably distinct structural, electronic, magnetic, and spectroscopic properties. At low temperature, LiOsO$_3$ is a polar bad metal with a rhombohedral $R3c$…

We report the emergence of a transverse dielectric response in PbTiO$_{3}$/SrTiO$_{3}$ superlattices hosting polar vortex structures. Using second-principles simulations, we find that an electric field applied along one direction induces…

We report the structural, elastic and vibrational properties of five ionic-molecular solid oxidizers MNO$_3$ (M = Li, Na, K) and MClO$_3$ (M = Na, K). By treating long range electron-correlation effects, dispersion corrected method leads to…

The interplay of electronic and structural degrees of freedom is a prominent feature of many quantum materials and of particular interest in systems with strong ferroelectric fluctuations, such as SrTiO$_3$ (STO) and KTaO$_3$ (KTO). Both…

We have studied the structural phase transition of multiferroic YMnO$_3$ from first principles. Using group-theoretical analysis and first-principles density functional calculations of the total energy and phonons, we perform a systematic…

Molecular-dynamics simulations of KNbO$_3$ reveal preformed dynamic chain-like structures, present even in the paraelectric phase, that are related to the softening of phonon branches over large regions of the Brillouin zone. The phase…

The phonon dispersion relation of NiTi in the simple cubic B2 structure is computed using first-principles density-functional perturbation theory with pseudopotentials and a plane-wave basis set. Lattice instabilities are observed to occur…

I study the structural and magnetic instabilities in LaNiO$_3$ using density functional theory calculations. From the non-spin-polarized structural relaxations, I find that several structures with different Glazer tilts lie close in energy.…

Perturbed angular correlation spectroscopy combined with $ab-initio$ electronic structure calculations is used to unravel the structural phase transition path from the low-temperature polar structure to the high-temperature structural phase…