Related papers: Spin singlet small bipolarons in Nb-doped BaTiO3

The temperature dependence of the low-temperature dielectric response is studied in o-TaS$_3$ samples doped by Nb, Se, and Ni and for nominally pure ones. It is found, that the low-temperature dielectric constant depends anomalously on…

We measure the temperature-dependent carrier density and resistivity of the topological surface state of thin exfoliated Bi2Se3 in the absence of bulk conduction. When the gate-tuned chemical potential is near or below the Dirac point the…

When electron doped, the layered transition metal nitrides ${\cal T}$NCl (${\cal T}$ = group IVB transition metal ion) become impressive superconductors with critical temperature T$_c$= 15-26K. Here we take the most studied member, ZrNCl,…

The electron's kinetic energy plays a pivotal role in magnetism. While virtual electron hopping promotes antiferromagnetism in an insulator, the real process usually favors ferromagnetism. But in kinetically frustrated systems, such as hole…

The dielectric properties of La$_{1-x}$Sr$_{1+x}$MnO$_4$ single crystals with x = 0, 0.125, 0.25, and 0.5 were studied by means of electron energy-loss spectroscopy as a function of temperature and momentum transfer. A clear signature of…

We developed a theory of electric and thermoelectric conductivity of lightly doped SrTiO$_3$ in the non-degenerate region $k_B T \geq E_F$, assuming that the major source of electron scattering is their interaction with soft transverse…

SrxBi2Se3 is recently reported to be a superconductor derived from topological insulator Bi2Se3. It shows a maximum resistive Tc of 3.25 K at ambient pressure. We report magnetic (upto 1 GPa) and transport properties (upro 8 Gpa) under…

The magneto-electric (ME) coupling on spin-wave resonances in single-crystal Cu2OSeO3 was studied by a novel technique using electron spin resonance combined with electric field modulation. An external electric field E induces a magnetic…

Examination of the electrical resistivities of iron pnictides shows that they can be accounted by conduction by polarons. Their activation energies show a linear behaviour with the critical temperatures of the spin density waves (SDW), T*,…

Neutron spectroscopy measurements reveal dynamic spin correlations throughout the Brillouin zone in the colossal magnetoresistive material La0.7Ca0.3MnO3 at 265 K (approximately 1.03 Tc). The long-wavelength behavior is consistent with spin…

The hexagonal polymorph of Ba$_3$Tb(BO$_3$)$_3$ contains Tb$^{3+}$ ions on a quasi-2D triangular lattice, resulting in geometric magnetic frustration. Powder samples of Ba$_3$Tb(BO$_3$)$_3$ have been investigated using specific heat, powder…

We report on the crystal growth and characterization of ABi3 (A=Ba,Sr) superconductors. Single crystals of both compounds were grown by the self-flux technique. BaBi3 crystallized in a tetragonal structure with space group P4/mmm and SrBi3…

In order to establish the correlation between the magnetoelectric coupling and magnetic instability, we have studied the structural, magnetic, and ferroelectric properties of \textit{x}BaTiO${_3}$-(1-\textit{x})BiCoO${_3}$ as a function of…

We present a study of the magnetic properties of the electron doped manganites Ca1-xYxMnO3 (for 0<=x<=0.25) in the paramagnetic regime. For the less doped samples (x<=0.1) the magnetic susceptibility, c(T), follows a Curie-Weiss (CW) law…

We report thermodynamic magnetization measurements of two-dimensional electrons in several high mobility Si metal-oxide-semiconductor field-effect transistors. We provide evidence for an easily polarizable electron state in a wide density…

Polar metals are rare because free carriers in metals screen electrostatic potential and eliminate internal dipoles. Degenerate doped ferroelectrics may create an approximate polar metallic phase. We use first-principles calculations to…

In the Mott-Hubbard insulators YTiO3 and SmTiO3 we study optical excitations from the lower to the upper Hubbard band, d^1d^1 -> d^0d^2. The multi-peak structure observed in the optical conductivity reflects the multiplet structure of the…

Large diameter single-wall boron nanotubes (SWBNT) produced by 2%Mg-mesoporous Al2O3 catalysis show diamagnetic transition at ~ 40 K and ~ 80 K, which is a serious indication for possible superconductivity (J.Phys.Chem.C113, (2009) 17661).…

We report the temperature dependence of the upper critical magnetic field in the quasi-onedimensional molecular organic superconductor (DMET)2I3, for magnetic field applied along the intrachain, interchain, and interplane directions. The…

We present a numerical treatment of a spin-orbital polaron model for Na_xCoO_2 at small hole concentration (0.7 < x < 1). We demonstrate how the polarons account for the peculiar magnetic properties of this layered compound: They explain…