Ning, F. L., Ahilan, K., Imai, T., Sefat, A. S., Jin, R., McGuire, M. A., ...
We report an NMR investigation of the superconductivity in BaFe(2)As(2) induced by Co doping (Tc=22K). We demonstrate that Co atoms form an alloy with Fe atoms and donate carriers without creating...
Temperature and Spatial Dependence of the Superconducting and Pseudogap of NdFeAsO0.86F0.14 (2008)
Pan, M. H., He, X. B., Li, G. R., Wendelken, J. F., Jin, R., Sefat, A. S., ...
The discovery of superconductivity with a critical temperature exceeding 55 K in the iron-oxypnictides and related compounds has quite suddenly given the community a new set of materials - breaking...
Observation of a novel orbital selective Mott transition in Ca$_{1.8}$Sr$_{0.2}$RuO$_4$ (2008)
Neupane, M., Richard, P., Xu, Y., Jin, R., Mandrus, D., ...
Electrons in a simple correlated system behave either as itinerant charge carriers or as localized moments. However, there is growing evidence for the coexistence of itinerant electrons and local...
Bondino, F., Magnano, E., Malvestuto, M., Parmigiani, F., McGuire, M. A., Sefat, A. S., ...
The discovery of superconductivity with a critical temperature exceeding 55 K in the iron-oxypnictides and related compounds has suddenly offered the community a new set of materials, breaking the...
Phonon Density of States of LaFeAsO1-xFx (2008)
Christianson, A. D., Lumsden, M. D., Delaire, O., Stone, M. B., Abernathy, D. L., McGuire, M. A., ...
We have studied the phonon density of states (PDOS) in LaFeAsO1-xFx with inelastic neutron scattering methods. The PDOS of the parent compound(x=0) is very similar to the PDOS of samples optimally...
Charge order in LuFe2O4: antiferroelectric ground state and coupling to magnetism (2008)
Angst, M., Hermann, R. P., Christianson, A. D., Lumsden, M. D., Lee, C., ...
X-ray scattering by multiferroic LuFe2O4 is reported. Below 320 K, superstructure reflections indicate an incommensurate charge order with propagation close to (1/3,1/3,3/2). The corresponding charge...
McGuire, M. A., Christianson, A. D., Sefat, A. S., Sales, B. C., Lumsden, M. D., Jin, R., ...
We present results from a detailed experimental investigation of LaFeAsO, the parent material in the series of ``FeAs'' based oxypnictide superconductors. Upon cooling this material undergoes a...
Jaroszynski, J., Riggs, S. C., Hunte, F., Gurevich, A., Larbalestier, D. C., Beobinger, G. S., ...
The recent discovery of a new class of superconducting oxypnictides with high transition temperatures may have profound implications for understanding unconventional high-temperature...
Zocco, D. A., Hamlin, J. J., Baumbach, R. E., Maple, M. B., McGuire, M. A., Sefat, A. S., ...
We have performed several high-pressure resistivity experiments on the recently discovered superconductors La[O_{0.89}F_{0.11}]FeAs and Ce[O_{0.88}F_{0.12}]FeAs. At ambient pressure, these materials...
Yamamoto, A., Jiang, J., Tarantini, C., Craig, N., Polyanskii, A. A., Kametani, F., ...
The new rare-earth arsenate superconductors are layered, low carrier density compounds with many similarities to the high-Tc cuprates. An important question is whether they also exhibit weak-coupling...
19-F NMR Investigation of Iron-pnictide Superconductor LaFeAsO(0.89)F(0.11) (2008)
Ahilan, K., Ning, F. L., Imai, T., Sefat, A. S., Jin, R., McGuire, M. A., ...
We report 19-F NMR investigation of the new high temperature superconductor LaFeAsO(0.89)F(0.11) (Tc ~ 28K). We demonstrate that low frequency spin fluctuations exhibit pseudo gap behavior above Tc....
Evidence for the Spin Density Wave in LaFeAsO (2008)
McGuire, M. A., Christianson, A. D., Sefat, A. S., Jin, R., Payzant, E. A., Sales, B. C., ...
This paper has been withdrawn by the authors due to errors in the X-ray diffraction data. Other measured data are not affected; however, the errors significantly change the interpretation and...
Very High Field Two-Band Superconductivity in LaFeAsO_0.89F_0.11 (2008)
Hunte, F., Jaroszynski, J., Gurevich, A., Larbalestier, D. C., Jin, R., Sefat, A. S., ...
The ongoing search for new superconductors has recently yielded a new family of oxypnictides composed of alternating La_2O_{2-x}F_x and Fe_2As_2 layers [1-4] with transition temperatures T_c of 25-28...
Three Dimensional Magnetic Correlations in Multiferroic LuFe2O4 (2007)
Christianson, A. D., Lumsden, M. D., Angst, M., Yamani, Z., Tian, W., Jin, R., ...
We present single-crystal neutron diffraction measurements on multiferroic LuFe2O4 showing phase transitions at 240 and 175 K. Magnetic reflections are observed below each transition indicating that...
Manifestations of Broken Symmetry: The Surface Phases of Ca(2-x)Sr(x)RuO4 (2007)
Moore, R. G., Nascimento, V. B., Zhang, Jiandi, Rundgren, J., Jin, R., Mandrus, D., ...
The surface structural phases of Ca(2-x)Sr(x)RuO(4) are investigated using quantitative Low Energy Electron Diffraction. The broken symmetry at the surface enhances the structural instability against...
Magnetic and orbital ordering in the spinel MnV2O4 (2007)
Garlea, V. O., Jin, R., Mandrus, D., Roessli, B., Huang, Q., Miller, M., ...
Neutron inelastic scattering and diffraction techniques have been used to study the MnV2O4 spinel system. Our measurements show the existence of two transitions to long-range ordered ferrimagnetic...
Coupling Between An Optical Phonon and the Kondo Effect (2007)
Burch, K. S., Chia, Elbert E. M., Talbayev, D., Sales, B. C., Mandrus, D., Taylor, A. J., ...
We explore the ultra-fast optical response of Yb_{14}MnSb_{11}, providing further evidence that this Zintl compound is the first ferromagnetic, under-screened Kondo lattice. These experiments also...
Incommensurate Charge Order Phase in Fe2OBO3 due to Geometrical Frustration (2007)
Angst, M., Hermann, R. P., Schweika, W., Khalifah, P., Xiang, H. J., ...
The temperature dependence of charge order in Fe2OBO3 was investigated by resistivity and differential scanning calorimetry measurements, Mossbauer spectroscopy, and synchrotron x-ray scattering,...
Charge Order Superstructure with Integer Iron Valence in Fe2OBO3 (2007)
Angst, M., Khalifah, P., Hermann, R. P., Xiang, H. J., Varadarajan, V., ...
Solution-grown single crystals of Fe2OBO3 were characterized by specific heat, Mossbauer spectroscopy, and x-ray diffraction. A peak in the specific heat at 340 K indicates the onset of charge order....
Moon, S. J., Choi, W. S., Kim, S. J., Lee, Y. S., Khalifah, P. G., Mandrus, D., ...
We investigated the electronic response of the quasi-two-dimensional spin gap compound La4Ru2O10 using optical spectroscopy. We observed drastic changes in the optical spectra as the temperature...
NaV2O4: a Quasi-1D Metallic Antiferromagnet with Half-Metallic Chains (2007)
Yamaura, K., Arai, M., Sato, A., Karki, A. B., Young, D. P., Movshovich, R., ...
NaV2O4 crystals were grown under high pressure using a NaCl flux, and the crystals were characterized with X-ray diffraction, electrical resistivity, heat capacity, and magnetization. The structure...
Quantum spin correlations in an organometallic alternating sign chain (2007)
Stone, M. B., Tian, W., Lumsden, M. D., Granroth, G. E., Mandrus, D., ...
High resolution inelastic neutron scattering is used to study excitations in the organometallic magnet DMACuCl$_3$. The correct magnetic Hamiltonian describing this material has been debated for many...
Acbas, G., Ohkubo, I., Christen, H., Mandrus, D., ...
We present measurement and analysis techniques that allow the complete complex magneto-conductivity tensor to be determined from mid-infrared (11-1.6 micron; 100-800 meV) measurements of the complex...
Wang, Feng, Allen, J. W., He, J., Jin, R., ...
Angle resolved photoemission spectroscopy (ARPES) has been performed on quasi-one dimensional Li0.9Mo6O17 using photon energy 500 eV. Measured band dispersions are in agreement with those from both...
Orbitally driven spin-singlet dimerization in $S$=1 La$_{4}$Ru$_{2}$O$_{10}$ (2006)
Wu, Hua, Hu, Z., Burnus, T., Denlinger, J. D., Khalifah, P. G., Mandrus, D., ...
Using x-ray absorption spectroscopy at the Ru-$L_{2,3}$ edge we reveal that the Ru$^{4+}$ ions remain in the $S$=1 spin state across the rare 4d-orbital ordering transition and spin-gap formation. We...
New Luttinger liquid physics from photoemission on Li$_{0.9}$Mo$_6$O$_{17}$ (2006)
Wang, Feng, Alvarez, J. V., Allen, J. W., He, J., ...
Temperature dependent high resolution photoemission spectra of quasi-1 dimensional Li$_{0.9}$Mo$_6$O$_{17}$ evince a strong renormalization of its Luttinger liquid density-of-states anomalous...
Temperature dependent bilayer ferromagnetism in Sr3Ru2O7 (2006)
Stone, M. B., Lumsden, M. D., Jin, R., Sales, B. C., Qiu, Y., Mandrus, D., ...
The Ruthenium based perovskites exhibit a wide variety of interesting collective phenomena related to magnetism originating from the Ru 4d electrons. Much remains unknown concerning the nature of...
Lattice vibrations in (La,Ce)Fe4Sb12 and CoSb3: Inelastic neutron scattering and theory (2006)
Feldman, J L, Dai, P, Enck, T, Sales, B C, Mandrus, D, Singh, D J
Magneto-Dielectric Effect in the S = 1/2 Quasi-Two Dimensional Antiferromagnet K2V3O8 (2005)
Rai, R. C., Cao, J., Musfeldt, J. L., Singh, D. J., Jin, R., Zhou, Z. X., ...
We report the optical and magneto-optical properties of K2V3O8, an S=1/2 quasi-two-dimensional Heisenberg antiferromagnet. Local spin density approximation electronic structure calculations are used...
Sushko, Y. V., Korneta, O. B., Leontsev, S. O., Jin, R., Sales, B. C., Mandrus, D.
The results of DC magnetization measurements under hydrostatic (helium-gas) pressure are reported for an ambient pressure superconductor Na0.35CoO2.1.4D2O and its precursor compound, the gamma-phase...
Kondo Lattice Behavior in the Ordered Dilute Magnetic Semiconductor Yb_{14-x}La_xMnSb_{11} (2005)
Sales, B. C., Khalifah, P., Enck, T. P., Nagler, E. J., Sykora, R. E., Jin, R., ...
We report Hall, magnetic, heat capacity and doping studies from single crystals of Yb_14MnSb_11 and Yb_13.3La_0.7MnSb_11. These heavily doped semiconducting compounds are ferromagnetic below 53 K and...
Optical study of interactions in a d-electron Kondo lattice with ferromagnetism (2005)
Burch, K. S., Schafgans, A., Butch, N. P., Sayles, T. A., Maple, M. B., Sales, B. C., ...
We report on a comprehensive optical, transport and thermodynamic study of the Zintl compound Yb$_{14}$MnSb$_{11}$, demonstrating that it is the first ferromagnetic Kondo lattice compound in the...
Optical study of interactions in a d-electron kondo lattice with ferromagnetism (2005)
Burch, Kenneth S, Schafgans, A, Butch, N P, Sayles, T A, Maple, M B, Sales, B C, ...
We report on a comprehensive optical, transport, and thermodynamic study of the Zintl compound Yb14MnSb11, demonstrating that it is the first ferromagnetic Kondo lattice compound in the underscreened...
Goldstone-Mode Phonon Dynamics in the Pyrochlore Cd2Re2O7 (2005)
Kendziora, C. A., Sergienko, I. A., Jin, R., He, J., Keppens, V., Sales, B. C., ...
We have measured the polarized Raman scattering spectra of Cd2Re2O7, the first superconducting pyrochlore, as a function of temperature. For temperatures below the cubic-to-tetragonal structural...
Sekharan, A. K. P., Sato, T., Souma, S., Takahashi, T., ...
We report a systematic angle-resolved photoemission study on Na$_x$CoO$_2$ for a wide range of Na concentrations ($0.3 \leq x \leq 0.72$). In all the metallic samples at different $x$, we observed...
Local structure of LiNiO2 studied by neutron diffraction (2005)
Proffen, Th., Shamoto, S., Ghorayeb, A. M., Croguennec, Laurence, Tian, W., ...
The nature of the magnetic state of LiNiO2 has been controversial. In this compound Ni spins (S = 1/2) form a triangular lattice with the possibility of magnetic frustration, but the exact state of...
Magnetism in purple bronze Li0.9Mo6O17 (2005)
Chakhalian, J., Salman, Z., Brewer, J., Froese, A., He, J., Mandrus, D., ...
Variation of Specific Heat with x and y in NaxCoO2-yH2O/D2O (2004)
Jin, R., Sales, B. C., Li, S., Mandrus, D.
We report specific heat measurements down to 0.4 K on the layered oxide Na$_x$CoO$_2\cdot\it{y}$H$_2$O/D$_2$O with 0 $\le$ $\it{x}$ $\le$ 0.74 and $\it{y}$ = 0 and 1.4. For the nonhydrated system...
Magnetism in purple bronze Li$_{0.9}$Mo$_6$O$_{17}$ (2004)
Chakhalian, J., Salman, Z., Brewer, J., Froese, A., He, J., Mandrus, D., ...
Muon spin relaxation measurements around the 25 K metal-insulator transition in Li$_{0.9}$Mo$_6$O$_{17}$ elucidate a profound role of disorder as a possible mechanism for this transition. The...
Fermi surface topology of Ca_{1.5}Sr_{0.5}RuO_{4} determined by ARPES (2004)
Sekharan, A. K. P., Souma, S., Matsui, H., Sato, T., ...
We report ARPES results of the Fermi surface of Ca_{1.5}Sr_{0.5}RuO$_{4}, which is at the boundary of magnetic/orbital instability in the phase diagram of the Ca-substituted Sr ruthenates. Three...
Four-Well Tunneling States and Elastic Response of Clathrates (2004)
Zerec,I., Keppens,V., McGuire,M. A., Mandrus,D., Sales,B. C., Thalmeier,P.
Four-well tunneling states and elastic response of clathrates (2004)
Zerec, I., Keppens, V., McGuire, M. A., Mandrus, D., Sales, B. C., Thalmeier, P.
We present resonant ultrasound elastic constant measurements of the clathrate compounds Eu8Ga16Ge30 and Sr8Ga16Ge30. The elastic response of the Eu clathrate provides clear evidence for the existence...
Allen, J. W., He, J., Jin, R., Mandrus, D., ...
Angle resolved photoemission spectroscopy line shapes measured for quasi-one-dimensional Li$_{0.9}$Mo$_6$O$_{17}$ samples grown by a temperature gradient flux technique are found to show Luttinger...
Evidence and Characterization of a SDW Transition in Na0.75CoO2 Single Crystals (2004)
Sales, B. C., Jin, R., Affholter, K. A., Khalifah, P., Veith, G. M., Mandrus, D.
The magnetic, thermal and transport properties of Na0.75CoO2 single crystals grown by the floating zone (FZ) method are reported. Magnetic susceptibility, resistivity, magnetoresistance, and heat...
Metallic "Ferroelectricity" in the Pyrochlore Cd2Re2O7 (2004)
Sergienko, I. A., Keppens, V., McGuire, M., Jin, R., He, J., Curnoe, S. H., ...
A class of materials known as ``ferroelectric metals'' was discussed theoretically by Anderson and Blount in 1965 [Phys. Rev. Lett. 14, 217 (1965)], but to date no examples of this class have been...
Sales, B., Jin, R., Mandrus, D.
The ability of an insulating solid to conduct heat is rarely effected by the application of a magnetic field. We have found, however, that the low temperature heat conduction of some solids increases...
Four-Well Tunneling States and Elastic Response of Clathrates (2004)
Zerec, I., Keppens, V., McGuire, M. A., Mandrus, D., Sales, B. C., Thalmeier, P.
Optical properties of pyrochlore oxide $Pb_{2}Ru_{2}O_{7-{\delta}}$ (2003)
Zheng, P., Wang, N. L., Luo, J. L., Jin, R., Mandrus, D.
We present optical conductivity spectra for $Pb_{2}Ru_{2}O_{7-{\delta}}$ single crystal at different temperatures. Among reported pyrochlore ruthenates, this compound exhibits metallic behavior in a...
Infrared probe of the electronic structure and charge dynamics in Na$_{0.7}$CoO$_2$ (2003)
Wang, N. L., Zheng, P., Wu, D., Ma, Y. C., Xiang, T., Jin, R. Y., ...
We present measurements of the optical spectra on Na$_{0.7}$CoO$_2$ single crystals. The optical conductivity shows two broad interband transition peaks at 1.6 eV and 3.2 eV, and a weak midinfrared...
Distribution of exchange energy in a bond-alternating S=1 quantum spin chain (2003)
Zheludev, A., Masuda, T., Sales, B., Mandrus, D., Papenbrock, T., Barnes, T., ...
The quasi-one-dimensional bond-alternating S=1 quantum antiferromagnet NTENP is studied by single crystal inelastic neutron scattering. Parameters of the measured dispersion relation for magnetic...
Sekharan, A. K. P., Matsui, H., Souma, S., Sato, T., ...
The electronic structure of single crystals Na$_{0.6}$CoO$_2$, which are closely related to the superconducting Na$_{0.3}$CoO$_2$.$y$H$_2$O ($T_c \sim 5K$), is studied by angle-resolved photoelectron...
Khalifah, P., Ohkubo, I., Christen, H., Mandrus, D.
A series of epitaxial films were grown across the solid solution Ca(x)Sr(1-x)RuO(3) in order to pinpoint the ferromagnetic to paramagnetic quantum phase transition in this system and to study the...
Jin, R., Sales, B. C., Khalifah, P., Mandrus, D.
Poly- and single-crystalline Na$_x$CoO$_2$ has been successfully intercalated with H$_2$O and D$_2$O as confirmed by X-ray diffraction and thermogravimetric analysis. Resistivity, magnetic...
The electrical properties of Cd2Re2O7 under pressure (2003)
Barisic, N., Forro, L., Mandrus, D., Jin, R., He, J., Fazekas, P.
We examine the resistivity and thermopower of single crystal specimens of the pyrochlore oxide Cd2Re2O7 at pressures up to 2GPa. Thermopower proves to be a sensitive tool in the study of the phase...
Einstein oscillators in thallium filled antimony skutterudites (2003)
Hermann, R. P., Jin, R., Schweika, W., Grandjean, W. B., Mandrus, D., Sales, B. C., ...
This version is available at the following Publisher URL: http://prl.aps.org
Optical evidence for mass enhancement of quasiparticles in pyrochlore Cd$_2$Re$_2$O$_7$ (2002)
Wang, N. L., McGuire, J. J., Timusk, T., Jin, R., He, J., Mandrus, D
We report on the results of optical studies of the newly discovered superconductor Cd$_2$Re$_2$O$_7$ in the normal state. We show that the compound has an exotic metallic state at low temperature....
Kang, H. J., Dai, Pengcheng, Mandrus, D., Jin, R., Mook, H. A., Adroja, D. T., ...
We use inelastic neutron scattering to study the evolution of the generalized phonon density of states (GDOS) of the $n$-type high-$T_c$ superconductor Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$ (NCCO), from...
Orbital-resolved Soft X-Ray Spectroscopy in NaV2O5 (2002)
Zhang, G. P., Woods, G. T., Shirley, Eric L., Callcott, T. A., Lin, L., Chang, G. S., ...
We demonstrate that angle-resolved soft x-ray spectroscopy can resolve absorption by inequivalent oxygen sites and by different orbitals belonging to the same site in NaV2O5. By rotating the...
Padilla, W. J., Basov, D. N., Mandrus, D.
Infrared reflectance measurements were made on the single crystal pyrochlore Cd$_{2}$Os$_{2}$O$_{7}$ in order to examine the transformations of the electronic structure and crystal lattice across the...
Structural Ordering and Symmetry Breaking in Cd_2Re_2O_7 (2002)
Castellan, J. P., Gaulin, B. D., Van Duijn, J., Lewis, M. J., Lumsden, M. D., Jin, R., ...
Single crystal X-ray diffraction measurements have been carried out on Cd_2Re_2O_7 near and below the phase transition it exhibits at Tc' ~195 K. Cd_2Re_2O_7 was recently discovered as the first, and...
Electron Correlation Effects in Resonant Inelastic X-ray Scattering of NaV2O5 (2002)
Zhang, G. P., Callcott, T. A., Woods, G. T., Lin, L., Sales, Brian, Mandrus, D., ...
Element- and site-specific resonant inelastic x-ray scattering spectroscopy (RIXS) is employed to investigate electron correlation effects in {$\rm NaV_2O_5$}. In contrast to single photon...