Multiferroic properties of an \aa kermanite Sr2_2CoSi2_2O7_7 single crystal in high magnetic fields

The magnetic and dielectric properties of \aa kermanite Sr$_2$CoSi$_2$O$_7$ single crystals in high magnetic fields were investigated. We have observed finite induced electric polarization along the c axis in high fields, wherein all Co spins were forcibly aligned to the magnetic field direction. Existence of the induced polarization in the spin-polarized state accompanied with the finite slope in the magnetization curve suggests the possible role of the orbital angular momenta in the excited states as its microscopic origin. The emergence of the field-induced polarization without particular magnetic order can be regarded as the magnetoelectric effects of the second order from the symmetry point of view. A low magnetic field-driven electric polarization flip induced by a rotating field, even at room temperature, has been successfully demonstrated.Comment: 12 pages, 4 figure

Magnetic-field-induced switching between ferroelectric phases in orthorhombic-distortion-controlled RRMnO3_{3}

We have investigated the dielectric and magnetic properties of Eu$_{0.595}$Y$_{0.405}$MnO$_{3}$ $without$ the presence of the 4$f$ magnetic moments of the rare earth ions, and have found two ferroelectric phases with polarization along the $a$ and $c$ axes in a zero magnetic field. A magnetic field induced switching from one to the other ferroelectric phase took plase in which the direction of ferroelectric polarization changed from the a axis to the c axis by the application of magnetic fields parallel to the a axis. In contrast to the case of TbMnO$_{3}$, in which the 4$f$ moments of Tb$^{3+}$ ions play an important role in such a ferroelectric phase switching, the magnetic-field-induced switching between ferroelectric phases in Eu$_{0.595}$Y$_{0.405}$MnO$_{3}$ does not originate from the magnetic transition of the rare-earth 4$f$ moments, but from that of the Mn 3$d$ spins.Comment: 8 pages, 3 figures, RevTeX4, Proceedings of MMM 2005, to appear in J. Appl. Phy

Global Journalist: Siege on Moscow amid global terrorism crisis

Global Journalist, October 31, 2002 show: On October 31, 2002, Chechen terrorist rebels sieged a theatre in Moscow taking hundreds of occupants hostage. Byron Scott discusses the media coverage of the Moscow theatre hostage crisis with Russian journalists and UN media correspondents. Amid the global rise of terrorism, Global Journalist raises concerns for media ethics and press freedom as tension increases between Chechnya and the Russian Federation. Host: Byron Scott. Guests: Akaki Gogichaishvili, Betsy Pisik, Alexander Merkushev, Andrei Zolotov. Producers: Sarah Fajardo. Directors: Pat Akers

Magnetic and Dielectric Properties in Multiferroic Cu3Mo2O9 under High Magnetic Fields

The magnetic and dielectric properties under high magnetic fields are studied in the single crystal of Cu3Mo2O9. This multiferroic compound has distorted tetrahedral spin chains. The effects of the quasi-one dimensionality and the geometrical spin frustration are expected to appear simultaneously. We measure the magnetoelectric current and the differential magnetization under the pulsed magnetic field up to 74 T. We also measure the electric polarization versus the electric field curve/loop under the static field up to 23 T. Dielectric properties change at the magnetic fields where the magnetization jumps are observed in the magnetization curve. Moreover, the magnetization plateaus are found at high magnetic fields.Comment: 6 pages, 3 figures, in press in JPS Conf. Proc. as a part of SCES2013 Proceeding

Theory of magnetoelectric resonance in two-dimensional S=3/2S=3/2 antiferromagnet Ba2CoGe2O7{\rm Ba_2CoGe_2O_7} via spin-dependent metal-ligand hybridization mechanism

We investigate magnetic excitations in an $S=3/2$ Heisenberg model representing two-dimensional antiferromagnet ${\rm Ba_2CoGe_2O_7}$. In terahertz absorption experiment of the compound, Goldstone mode as well as novel magnetic excitations, conventional magnetic resonance at 2 meV and both electric- and magnetic-active excitation at 4 meV, have been observed. By introducing a hard uniaxial anisotropy term $\Lambda (S^z)^2$, three modes can be explained naturally. We also indicate that, via the spin-dependent metal-ligand hybridization mechanism, the 4 meV excitation is an electric-active mode through the coupling between spin and electric-dipole. Moreover, at 4 meV excitation, an interference between magnetic and electric responses emerges as a cross correlated effect. Such cross correlation effects explain the non-reciprocal linear directional dichroism observed in ${\rm Ba_2CoGe_2O_7}$.Comment: 5 pages, 3 figure

Influence of household demographic and socio-economic factors on household expenditure on tobacco in six New Independent States

<p>Abstract</p> <p>Background</p> <p>To identify demographic and socio-economic factors that are associated with household expenditure on tobacco in Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Russian Federation, and Tajikistan.</p> <p>Methods</p> <p>Secondary analysis of the data available through the World Bank Living Standards Monitoring Survey conducted in aforementioned countries in 1995–2000. The role of different variables (e.g. mean age of household members, household area of residence, household size, share of adult males, share of members with high education) in determining household expenditure on tobacco (defined as tobacco expenditure share out of total monthly HH consumption) was assessed by using multiple regression analysis.</p> <p>Results</p> <p>Significant differences were found between mean expenditure on tobacco between rich and poor – in absolute terms the rich spend significantly more compared with the poor. Poor households devote significantly higher shares of their monthly HH consumption for tobacco products. Shares of adult males were significantly associated with the share of household consumption devoted for tobacco. There was a significant negative association between shares of persons with tertiary education within the HH and shares of monthly household consumption devoted for tobacco products. The correlation between household expenditures on tobacco and alcohol was found to be positive, rather weak, but statistically significant.</p> <p>Conclusion</p> <p>Given the high levels of poverty and high rates of smoking in the New Independent States, these findings have important policy implications. They indicate that the impact and opportunity costs of smoking on household finances are more significant for the poor than for the rich. Any reductions in smoking prevalence within poor households could have a positive economic impact.</p

Solving integral equations in η→3π\eta\to 3\pi

A dispersive analysis of $\eta\to 3\pi$ decays has been performed in the past by many authors. The numerical analysis of the pertinent integral equations is hampered by two technical difficulties: i) The angular averages of the amplitudes need to be performed along a complicated path in the complex plane. ii) The averaged amplitudes develop singularities along the path of integration in the dispersive representation of the full amplitudes. It is a delicate affair to handle these singularities properly, and independent checks of the obtained solutions are demanding and time consuming. In the present article, we propose a solution method that avoids these difficulties. It is based on a simple deformation of the path of integration in the dispersive representation (not in the angular average). Numerical solutions are then obtained rather straightforwardly. We expect that the method also works for $\omega\to 3\pi$.Comment: 11 pages, 10 Figures. Version accepted for publication in EPJC. The ancillary files contain an updated set of fundamental solutions. The numerical differences to the former set are tiny, see the READMEv2 file for detail