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Seoungsu Lee, Taekjib Choi, William D. Ratcliff, Ross W. Erwin, S W. Cheong, V. Kiryukhin
We report on polarized neutron-scattering and piezoresponse force microscopy studies of millimeter-sized single crystals of multiferroic BiFeO3. The crystals, grown below the Curie temperature, consist of a single ferroelectric domain. Two unique electric
Hao Sha, F Ye, Pengcheng Dai, J. A. Fernandez-Baca, D Mesa, Jeffrey Lynn, Y Tomioka, Y Tokura, Jiandi Zhang
Neutron scattering has been used to investigate the evolution of long- and short-range charge-ordered (CO), ferromagnetic, and antiferromagnetic (AF) correlations in single crystals of Pr1−xCaxMnO3. The existence and population of spin clusters as
Yiming Qiu, M. Kofu, Wei Bao, S.-H. Lee, Qingzhen Huang, Taner N. Yildirim, John R. Copley, Jeffrey Lynn, T. Wu, G. Wu, X. H. Chen
The recently discovered superconductor LaO0.87F0.13FeAs (TC≈26 K) was investigated using the neutron-scattering technique. No spin-density-wave (SDW) order was observed in the normal state or in the superconducting state, both with and without an applied
We report neutron diffuse scattering measurements on a single crystal of 68%Pb(Mg1/3Nb2/3)O3- 32%PbTiO3. Strong diffuse scattering is observed at low temperatures. An external field applied along the [001] direction affects the diffuse scattering in the
Ying Chen, Jeffrey Lynn, Jiying Li, G. J. Li, G. F. Chen, J. L. Luo, N. L. Wang, Pengcheng Dai, Clarnia dela Cruz, H. A. Mook
Polarized and unpolarized neutron diffraction measurements have been carried out to investigate the iron magnetic order in undoped NdOFeAs. Antiferromagnetic order is observed below 141(6) K, which is in close proximity to the structural distortion
From all-electron fixed-spin-moment calculations we show that ferromagnetic and checkerboard antiferromagnetic ordering in LaFeAsO are not stable and the stripe antiferromagnetic configuration with is the only stable ground state. The main exchange
Wei Zhou, Hui Wu, Taner Yildirim, Jeffrey R. Simpson, Angela R. Hight Walker
Metal-organic framework-5 (MOF-5) was recently suggested to possess an exceptionally large negative thermal expansion coefficient. Our direct experimental measurement of the thermal expansion of MOF-5, using neutron powder diffraction, in the temperature
C. Sudakar, K. Pradmanabhan, R Naik, G Lawes, Brian Kirby, Sanjiv Kumar, V. M. Naik
We investigated the magnetic properties of CuO–ZnO heterostructures to elucidate the origin of the ferromagnetic signature in Cu doped ZnO. The CuO and ZnO layer thickness were varied from 15 to 150 nm and from 70 to 350 nm, respectively. Rutherford
M. B. Stone, M. D. Lumsden, Sung Chang, E. C. Samulon, C. D. Batista, I. R. Fisher
We present single crystal inelastic neutron scattering measurements of the S=1 dimerized quasi-two-dimensional antiferromagnet Ba3Mn2O8. The singlet-triplet dispersion reveals nearest-neighbor and next-nearest-neighbor ferromagnetic interactions between
Shannon Watson, T. Hauet, Julie A. Borchers, S Mangin, Eric E. Fullerton
Using magnetometry and polarized neutron reflectometry (PNR), we have mapped the reversal processes of the antiferromagnetically coupled, hard/soft system, TbFeCo/[Co/Pd(tpd)}15, with perpendicular anisotropy. The magnitude of the exchange coupling within
Seoungsu Lee, William D. Ratcliff, S.-W. Cheong, V. Kiryukhin
Single crystals of multiferroic BiFeO 3 were investigated using neutron scattering. Application of an electric field reversibly switches ferroelastic domains, inducing changes in the magnetic structure which follows rotation of the structural domains. In
Robert F. Berg, Michael R. Moldover, M Yao, G A. Zimmerli
We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids, near the critical point of xenon. The data span the range of reduced shear rates: 0.001 < γτ < 700, where γτ is the shear rate scaled by the relaxation time τ of
William P. Krekelberg, Vincent K. Shen, Jeffrey R. Errington, Thomas M. Truskett
The residual multiparticle entropy (RMPE) of two- and three-dimensional fluids changes sign near the freezing line, providing a quasi-universal one-phase rule for the location of the liquid-solid transition. We present new simulation results ford
Chunxia Chen, Praveen Depa, Janna K. Maranas, Victoria G. Sakai
We evaluate explicit atom, united atom, and coarse-grained force fields for molecular dynamics simulation of poly(methyl methacrylate)(PMMA)by comparison to structural and dynamic neutron scattering data. The coarse-grained force field is assigned based on
Nathan A. Tomlin, James A. Beall, Gene C. Hilton, Kent D. Irwin, Galen O'Neil, Dan Schmidt, Leila R. Vale, Joel Ullom
We demonstrate successful cooling of an X-ray transition-edge sensor (TES) using solid-state refrigerators based on normal-metal/insulator/superconductor (NIS) tunnel junctions. Above the TES transition temperature (Tc), we use Johnson noise thermometry to
Vincent K. Shen, Raymond D. Mountain, Jeffrey R. Errington
We report results from a comparative study of the influence of tail corrections on the surface tension of the Lennard-Jones fluid. We find that cutoff-independent surface tensions can be obtained by applying a set of tail corrections recently introduced by
Cosputtered Amorphous NbxSi1-x has been developed as a barrier material for Josephson junction array circuits. This material is not only promising as a normal-metal barrier for state-of-the-art Josephson voltage standard circuits, but the capability of
The scanning tunneling microscope [STM] is widely used in both industrial and fundamental research to obtain atomic-scale images of metal surfaces. It provides a three-dimensional profile of the surface which is very useful for characterizing surface
Keith A. Gillis, Iosif I. Shinder, Michael R. Moldover
We measured the resonance spectrum of an acoustic resonator filled with xenon near its critical temperature Tc. We reduced the effect of gravity on the xenon by convective stirring to achieve a temperature resolution of (T-Tc)/Tc 7 10-6. The data yield
The low-temperature rates for site-to-site transfer of single atoms and molecules adsorbed on surfaces have been determined in recent scanning tunneling microscopy (STM) studies within the temperature regime where the dominant transfer mechanism changes
Molecular dynamics simulation is used to calculate the infinite-dilution diffusivity of sodium hydroxide (NaOH) in steam at conditions of temperature and density typical of steam turbines. These data are needed in order to better understand deposition
Vibrationally resonant sum frequency generation (VR-SFG) is used to determine the structure of the phenyl side groups of deuterated polystyrene at the liquid/solid interface for the nonsolvent liquids: hexane, methanol, ethanol, glycerol, and water. The
Orhan Kizilkaya, Dustin Hite, David M. Zehner, Phillip T. Sprunger
The surface geometric and electronic structure of the FeAl(110) intermetallic alloy has been investigated by scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES). Preferential sputtering results in a depletion of Al in
The polarization of a nearest-neighbor (nn) Pb-O vacancy pair in PbTiO3 is calculated, using the modern theory of polarization, implemented in the density functional theory ultrasoft pseudopotential formalism. The dipole moment per divacancy is about 2.228
We study the ferroelectric phase transition in PbSc1/2Nb1/2O3 (PSN) using a first-principles effective Hamiltonian approach. Results for PSN with NaCl-type ordering of Sc and Nb on the B sites shows that a Pb-centered effective Hamiltonian is appropriate