Materials Literature
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Magnetization curves up to 25 T at 4.2 K are reported for mixed-valence manganites (R0.7A0.3)MnO3. All the R=La compounds show an extrapolated ferromagnetic moment of ∼3.4 μB/f.u. The A=Sr and Ca compounds show essentially no high-field slope, dM/dB<0.001 μB/T whereas the Pb and Ba compounds show slopes of 0.00…
The electronic structures in chiral carbon nanotubes are obtained by using the Su-Schrieffer-Heeger model with the Coulomb interaction included. The periodic boundary condition is applied for the direction of the tubular axis. The third-order polarizabilities of chiral carbon nanotubes are calculated by using the elec…
We systematically study transport and optical properties of charge-transfer salts, (Me 2 -DCNQI) 2 Li 1- x Cu x (0≤ x ≤1). The temperature dependence of electrical resistivity exhibits semiconducting behavior at x =0, a metal-semiconductor transition for 0.08≤ x ≤0.29, and metallic behavior down to 4.2 K for x ≥0.39.…
An effective low-energy Hamiltonian of interacting electrons in conducting single-wall carbon nanotubes with arbitrary chirality is derived from the microscopic lattice model. The parameters of the Hamiltonian show very weak dependence on the chiral angle, which makes the low-energy properties of conducting chiral nan…
Substitution of Ni for Mn in La0.67Sr0.33MnO3 (LSMO) lowers the Curie temperature TC from 365 K for LSMO to 194 K for La0.67Sr0.33(Mn0.8Ni0.2)O3, which exhibits a cluster glass-like state. The oxide is insulating under both zero field and 60 kOe, but application of the magnetic field induces colossal magnetoresistance…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSynthesis of Polymethylene Block Copolymers by the Polyhomologation of OrganoboranesKenneth J. Shea, Chad L. Staiger, and Sun Y. LeeView Author Information Department of Chemistry, University of California, Irvine, Irvine, Californi…
The local structure of erbium-doped silicon produced by the laser ablation technique is investigated by Er LIII-edge x-ray absorption fine structure analysis. The combined analysis of extended x-ray absorption fine structure analysis and an x-ray absorption near-edge structure simulation based on multiple-scattering t…
MnZn–ferrite has been prepared via high-energy ball milling of elemental oxides MnO, ZnO, and α-Fe2O3. Neutron diffraction measurements suggest a high density of vacancies in a spinel structure. The spinel phase appears to comprise 99.8 wt % of the material in the sample milled for 40 h, with the remainder attributabl…
Cluster-assembled carbon films deposited at room temperature from a supersonic cluster beam are found to be good electron field emitters. The films have been characterized by Raman spectroscopy showing a largely sp 2 bonded character. Scanning Electron Microscopy shows that the films have a low-density granular struct…
We develop a phase-field approach for solid-liquid interfaces under stress. We show various dynamics that are accessible within this approach. A typical example is a solid subject to uniaxial stress. We demonstrate the Asaro-Tiller-Grinfeld instability and a transition to fracture. Our approach can readily be extended…
For this study La0.7Ca0.3MnO3−δ (LCMO) films of various thicknesses were deposited on SrTiO3(100), LaAlO3(100), and MgO(100) substrates. The substrate–film lattice mismatch causes changes in the microstructure of the films and can therefore influence their magnetoresistive behavior. The structure of the films was char…
Multilayers combining exchange-coupled giant magnetostrictive materials (amorphous TbFe) and materials with large magnetic polarizations (FeCo or FeCoBSi) exhibit significant improvements in terms of low field magnetostriction and magnetostrictive susceptibility compared to state-of-the-art giant magnetostrictive sing…
The large HAD (haloacid dehalogenase) superfamily of hydrolases comprises P-type ATPases, phosphatases, epoxide hydrolases and L-2-haloacid dehalogenases. A comparison of the three-dimensional structure of L-2-haloacid dehalogenase with that of the response regulator protein CheY allowed the assignment of a conserved…
The Hall resistivity ρxy of a La2/3(Ca,Pb)1/3MnO3 single crystal has been measured as a function of temperature and field. The overall behavior is similar to that observed previously in thin-film samples. At 5 K, ρxy is positive and linear in field, indicating that the anomalous contribution is negligible. However, th…
The iron(III) S=5/2 dimer [Fe(OMe)(dbm)2]2 (in short Fe2) has a nonmagnetic S=0 ground state. The separation between the singlet ground state and the first excited (triplet) state is determined from susceptibility measurements to be about 22 K; for a dimer this value is equal to the antiferromagnetic exchange constant…
Semiempirical (MNDO, AM1 and PM3), ab initio (HF/3-21+G(d,p), MP2/3-21+G(d,p), HF/6-311+G(d,p), and MP2/6-311+G(d,p)), and density functional (BVWN/3-21+G(d,p) and BVWN/6-311+G(d,p)) energy minimization and frequency calculations have been carried out on AlCl(3), AlCl(4)(-), AlCl(2)(+), HAlCl(4), HAlCl(3)(+), and ClHA…
A model based on the domain wall pinning magnetomechanical hysteresis model of Sablik and Jiles [M. J. Sablik and D. C. Jiles, IEEE Trans. Magn. 29, 2113 (1993)] was formulated to compute changes in magnetic hysteresis under biaxial stress conditions with the magnetic field and stress axes noncoaxial. The model includ…
The magnetization and magnetostriction of a variety of 3/16-in.-diam Laves phase rods of TbxDyyHo1−x−yFe1.95 grown in the form of [112] oriented dendritic compounds were measured as a function of applied magnetic field −3000<H<3000 Oe and compressive stresses of 22 and 47 MPa at room temperature. Compare…
High-precision thermal conductivity measurements have been performed on a single crystal of ${\mathrm{La}}_{1.67}{\mathrm{Sr}}_{0.33}{\mathrm{NiO}}_{4}$ as well as on polycrystalline samples of ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{NiO}}_{4}(x=0.33,1)$ and ${\mathrm{Sr}}_{1.5}{\mathrm{La}}_{0.5}{\…
The properties of thin films of BaScxFe12−xO19 (x=0.4) were determined by structural and magnetic measurements. Films were deposited by pulsed laser ablation deposition onto c-plane sapphire at oxygen pressures between 10 and 100 mTorr. X-ray diffraction measurements showed all films to be single-phase c-axis oriented…