相关论文: Strain-induced heteronuclear charge disproportiona…

We show that the transition in AMnO3 from the orthorhombic perovskite phase to the hexagonal phase is promoted by inducing disorder on the A-site. The gap between the orthorhombic and the hexagonal phase is widened for disordered, mixed…

Perovskites with Bi or Pb on the A-site host a number of interesting and yet to be understood phenomena such as negative thermal expansion in BiNiO$_3$. We employ hard x-ray photoemission spectroscopy of Ni 2$p$ core-level as well as…

Emergent magnetic states at oxide interfaces arise from the interplay of charge transfer, orbital reconstruction, and dimensional confinement, offering a route to engineered correlated-electron behavior in nanoscale spintronic materials.…

Iron perovskites CaFeO_3 and La_{0.33}Sr_{0.67}FeO_3 show charge disproportionation, resulting in charge-ordered states with Fe^{3+}:Fe^{5+} =1:1 and =2:1, respectively. We have made photoemission and unrestricted Hartree-Fock…

We have investigated dielectric properties in a series of crystals of $R$MnO$_{3}$ ($R$ is a rare earth ion) under magnetic fields and quasihydrostatic pressure. We have found that ferroelectric phase appeared in GdMnO$_3$ crystal below…

The electric field control of functional properties is a crucial goal in oxide-based electronics. Non-volatile switching between different resistivity or magnetic states in an oxide channel can be achieved through charge accumulation or…

Controlling the optical properties of rare-earth ions in wide-bandgap semiconductors remains a major challenge in the development of next-generation photonic materials. Here, we show that external hydrostatic pressure modulates the…

We study the influence of external pressure on the electronic and magnetic structure of EuMnO3 from first-principles calculations. We find a pressure-induced insulator-metal transition at which the magnetic order changes from A-type…

The discovery of ferroelectric HfO2 in thin films and more recently in bulk is an important breakthrough because of its silicon-compatibility and unexpectedly persistent polarization at low dimensions, but the origin of its ferroelectricity…

Neutron scattering has been used to study the nature of the ferromagnetic transition in single crystals of La_0.7Ca_0.3MnO_3 and La_0.8Ca_0.2MnO_3, and polycrystalline samples of La_0.67Ca_0.33MnO_3 and La_5/8Ca_3/8MnO_3 where the naturally…

The crystal structure of CH3NH3PbBr3 perovskite has been investigated under high-pressure by synchrotron-based powder X-ray diffraction. We found that after the previously reported phase transitions in CH3NH3PbBr3 (Pm-3m->Im-3->Pmn21),…

Emergent phenomena at polar-nonpolar oxide interfaces have been studied intensely in pursuit of next-generation oxide electronics and spintronics. Here we report the disentanglement of critical thicknesses for electron reconstruction and…

The archetypal $3d$ Mott insulator hematite, Fe$_2$O$_3$, is one of the basic oxide components playing an important role in mineralogy of Earth's lower mantle. Its high pressure-temperature behavior, such as the electronic properties,…

We consider how the occurrence of first-order phase transitions in non-constant pressure differs from those at constant pressure. The former has shown the non-linear phase structure of mixed matter, which implies a particle number…

Li$_2$MnO$_3$ is a key component of Li-excess layered cathodes of the form $(1-x),\mathrm{LiMO_2} + x,\mathrm{Li_2MnO_3}$ ($M$ = Mn, Ni, Co, \dots), yet its role in setting Li-ion transport limitations remains under debate. Here we combine…

Crystal-field excitations, for example in transition-metal oxides where a rare-earth element is used as a spacer between the transition-metal-oxide tetrahedra and octahedra, are assumed to be extremely robust with respect to external…

Data for inelastic processes due to hydrogen atom collisions with iron are needed for accurate modelling of the iron spectrum in late-type stars. Excitation and charge transfer in low-energy Fe+H collisions is studied theoretically using a…

Here a recently observed weak first order transition in doped SrTiO3 is argued to be a consequence of the coupling between strain and order parameter fluctuations. Starting with a semi-microscopic action, and using renormalization group…

We present a theoretical study of charge transfer in collisions of excited ($n=2,3$) hydrogen atoms with He$^+$ and in collisions of excited ($n=2,3$) helium atoms with H$^+$, extending the results of Phys. Rev. A 82 012708 (2010). A…

Previous study of properties of the first-order phase transition in a set of plasma mod-els with common feature - absence of individual correlations between charges of opposite sign, was continued. Predicted discontinuities in equilibrium…