Search Results - (Author, Cooperation:U. Staub)
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1Latest Papers from Table of Contents or Articles in PressV. Esposito, L. Rettig, E. Abreu, E. M. Bothschafter, G. Ingold, M. Kawasaki, M. Kubli, G. Lantz, M. Nakamura, J. Rittman, M. Savoini, Y. Tokura, U. Staub, S. L. Johnson, and P. Beaud
American Physical Society (APS)
Published 2018Staff ViewPublication Date: 2018-02-01Publisher: American Physical Society (APS)Print ISSN: 1098-0121Electronic ISSN: 1095-3795Topics: PhysicsKeywords: Dynamics, dynamical systems, lattice effectsPublished by: -
2Latest Papers from Table of Contents or Articles in PressA. Rodriguez-Fernandez, V. Esposito, D. F. Sanchez, K. D. Finkelstein, P. Juranic, U. Staub, D. Grolimund, S. Reiche, B. Pedrini
Wiley-Blackwell
Published 2018Staff ViewPublication Date: 2018-02-24Publisher: Wiley-BlackwellTopics: Chemistry and PharmacologyGeosciencesPhysicsPublished by: -
3Latest Papers from Table of Contents or Articles in PressM. Porer, M. Fechner, E. M. Bothschafter, L. Rettig, M. Savoini, V. Esposito, J. Rittmann, M. Kubli, M. J. Neugebauer, E. Abreu, T. Kubacka, T. Huber, G. Lantz, S. Parchenko, S. Grübel, A. Paarmann, J. Noack, P. Beaud, G. Ingold, U. Aschauer, S. L. Johnson, and U. Staub
American Physical Society (APS)
Published 2018Staff ViewPublication Date: 2018-08-04Publisher: American Physical Society (APS)Print ISSN: 0031-9007Electronic ISSN: 1079-7114Topics: PhysicsKeywords: Condensed Matter: Structure, etc.Published by: -
4Latest Papers from Table of Contents or Articles in PressT. Kubacka ; J. A. Johnson ; M. C. Hoffmann ; C. Vicario ; S. de Jong ; P. Beaud ; S. Grubel ; S. W. Huang ; L. Huber ; L. Patthey ; Y. D. Chuang ; J. J. Turner ; G. L. Dakovski ; W. S. Lee ; M. P. Minitti ; W. Schlotter ; R. G. Moore ; C. P. Hauri ; S. M. Koohpayeh ; V. Scagnoli ; G. Ingold ; S. L. Johnson ; U. Staub
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-03-08Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
5Latest Papers from Table of Contents or Articles in PressN. Gurung, N. Leo, S. P. Collins, G. Nisbet, G. Smolentsev, M. García-Fernández, K. Yamaura, L. J. Heyderman, U. Staub, Y. Joly, D. D. Khalyavin, S. W. Lovesey, and V. Scagnoli
American Physical Society (APS)
Published 2018Staff ViewPublication Date: 2018-09-12Publisher: American Physical Society (APS)Print ISSN: 1098-0121Electronic ISSN: 1095-3795Topics: PhysicsKeywords: Electronic structure and strongly correlated systemsPublished by: -
6Latest Papers from Table of Contents or Articles in PressV. Scagnoli ; U. Staub ; Y. Bodenthin ; R. A. de Souza ; M. Garcia-Fernandez ; M. Garganourakis ; A. T. Boothroyd ; D. Prabhakaran ; S. W. Lovesey
American Association for the Advancement of Science (AAAS)
Published 2011Staff ViewPublication Date: 2011-04-09Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
7Articles: DFG German National LicensesMesot, J. ; Allenspach, P. ; Staub, U. ; Furrer, A. ; Mutka, H.
[S.l.] : American Institute of Physics (AIP)
Published 1993Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Inelastic neutron scattering has been employed to study the crystalline-electric-field (CEF) level scheme of Er3+ in ErBa2Cu3Ox (6〈x〈7). We have been able to resolve all the seven ground-state CEF transitions for a series of samples covering the superconducting as well as the semiconducting phases. All the CEF transitions are characterized by a monotonic behavior of their energies and intensities versus the oxygen content x, with the exception of the lowest-lying CEF state which exhibits a most unusual behavior: when going from x=7 to x=6, we observe a major shift to lower energies and a significant decrease of the intensity: moreover, there is evidence for real substructures associated with this CEF transition as shown in Fig. 1. More specifically, we find the observed energy spectra to be the result of a superposition of three stable states, whose spectral weights distinctly depend on the oxygen content x. We identify the three stable states A1, A2, and A3 by two local regions of metallic (Tc≈90 K, Tc≈60 K) and a local region of semiconducting character, respectively, i.e., there is clear experimental evidence for phase separation. The superconducting phases are shown to result from the formation of a two-dimensional percolative network. A bond percolation model correctly predicts the critical oxygen concentrations associated with the two-plateau structure of Tc. A preliminary account of the present work has recently been published.1Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesStaub, U. ; Fauth, F. ; Guillaume, M. ; Mesot, J. ; Furrer, A. ; Dosanjh, P. ; Zhou, H.
[S.l.] : American Institute of Physics (AIP)
Published 1993Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Inelastic neutron scattering has been employed to study the magnetic excitations of Ho3+ in a grain-aligned sample of the high-Tc compound HoBa2Cu3O7. From these measurements, we derive direct information on the anisotropic nature of the pair coupling within the rare-earth sublattice. The HoBa2Cu3O7 sample was grain-aligned at high temperatures under the action of an external field. This procedure resulted in an alignment of the grains along the z axis, whereas the x and y axes remained randomly oriented. We have particularly chosen HoBa2Cu3O7, since its crystal-field level scheme is well-established and characterized by a series of low-lying states1 which can be sufficiently resolved to detect even very small dispersion effects. The dispersive behavior of the Γ3→Γ4 crystal-field excitation is exemplified in Fig. 1 for various values of Q=(x',z), x'=(square root of)x2+y2, at T=1.5 K. The absence of energy dispersion along the z axis proves the predominantly 2D nature of the magnetic coupling between the Ho3+ ions, as actually expected from their large separation along the z axis. The observed energy spectra correspond to a superposition of transverse and longitudinal components which we have been able to separate through selected scans in Q space. Nearest-neighbor exchange parameters are estimated on the basis of an effective two-level model. The coupling of the Ho spins turns out to be extremely anisotropic.2Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesKlimenko, A. G. ; Ishikaev, S. M. ; Tagaev, A. B. ; Vasilyeva, I. G. ; Karpenko, M. M. ; Fischer, P. ; Furrer, A. ; Staub, U.
[S.l.] : American Institute of Physics (AIP)
Published 1991Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Physical properties of platelike single crystals (size up to 3×0.2×2 mm3, b axis perpendicular to the plate) of α-CeS2 (monoclinic, space group P21/c) have been studied and magnetic ordering was found below 7 K. Specific heat Cp(T) has a λ-type anomaly at TN=6.7 K with entropy sm=0.94R ln 2 and an additional maximum at 6.0 K (S'm ∼ 0.02R ln 2). Crystal-field splitting of the 2F5/2 state of Ce3+ into three doublets with energy levels 0, 230, and 415 cm−1 was obtained from Cp(T). Magnetic properties were studied using SQUID and vibrating sample magnetometer. Paramagnetic susceptibility obeys a Curie–Weiss law with anisotropic effective magnetic moment and Curie–Weiss temperature: P=2.1 μB, aitch-theta=+7.8 K for b axis and P=1.5 μB, aitch-theta=−0.8 K in directions perpendicular to the b axis. Complicated magnetic behavior is observed in low fields (0.1–100 Oe) below TN (strong dependence of dc susceptibility on thermomagnetic prehistory, cooling rate and applied field, remanent and memory phenomena). Magnetization curves at 4.2 K show a sharp metamagnetic transition at Hc=5 kOe for a field along the b axis and linear dependence M(H) up to 30 kOe for the perpendicular direction. Neutron scattering experiments are in progress to establish details of the magnetic structure and the crystal-field splitting.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesAllenspach, P. ; Mesot, J. ; Staub, U. ; Furrer, A.
[S.l.] : American Institute of Physics (AIP)
Published 1991Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Charge fluctuations and charge transfer processes appear to be important mechanisms towards understanding high-Tc superconductivity.1 We describe the inelastic-neutron-scattering technique to observe the crystalline electric field (CEF) as a direct probe of the local symmetry and charge distribution at the rare-earth site. For RBa2Cu3Ox (R=Ho,Er; 6〈×〈7) we have succeeded to directly prove the oxygen-vacancy-induced charge redistribution in the CuO2 planes,2,3 which support the idea of charge transfer from the chains to the planes.4 An empirical relation between Tc and the observed charge transfer Δρ3 is derived which is highly nonlinear close to Tc=90 K.3 Charge transfer can also be realized by pressure and doping (at the Cu sites). Neutron spectroscopic CEF studies performed under pressure up to 10 kbar and with doped systems RBa2Cu3−xMxO7 (M=Ni,Zn) as well as CEF studies on RBa2Cu4O8 compounds can be consistently described within our picture. Similarly, we have analyzed the neutron spectroscopic data available for the recently discovered high-Tc cuprates Nd2−xCexCuO4 and found direct evidence for the electron doping process occurring in the copper-oxide planes.〈ks〉Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaub, U. ; Fauth, F. ; Guillaume, M. ; Mesot, J. ; Furrer, A. ; Dosanjh, P. ; Zhou, H. ; Vorderwisch, P.
[S.l.] : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Inelastic neutron scattering has been employed to study the magnetic excitations of Ho3+ in a grain-aligned sample of HoBa2Cu3O7. The lowest lying branch exhibits dispersion for spin waves propagating in the (a,b) plane, whereas excitations along the c axis remain constant in energy. The data are analyzed in the random phase approximation in terms of the Heisenberg and an anisotropic model, resulting in an enormous spatial anisotropy of the magnetic coupling parameters, which are weakly ferromagnetic, antiferromagnetic, and almost zero for nearest-neighbor Ho3+ pairs along the a, b, and c axes, respectively. In addition, we have been able to separate the spin wave excitations in longitudinal and transverse parts.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesRoessli, B. ; Fischer, P. ; Staub, U. ; Zolliker, M. ; Furrer, A.
[S.l.] : American Institute of Physics (AIP)
Published 1994Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Magnetic ordering of HoBa2Cu3Ox (x=7.0,6.8,6.3) was investigated by means of neutron diffraction. Long-range antiferromagnetism is found for x=7.0 below TN=190 mK and for x=6.8 below TN=100 mK corresponding to propagation vector K=[0,1/2,1/2] with magnetic moment directions parallel to the a axis. The observed temperature dependence of the magnetic order parameter is in excellent agreement with mean-field calculations taking into account crystal field, exchange, and hyperfine interactions. No magnetic superlattice reflections were detected for x=6.3. A highly unusual ordering behavior is observed in HoBa2Cu3Ox (x=7.0,6.8) where the three-dimensional magnetic ordering is imperfect, due to finite correlation length ξc=29 and 129 A(ring), respectively, along the c axis.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesAllenspach, P. ; Mesot, J. ; Staub, U. ; Furrer, A. ; Blank, H. ; Mutka, H. ; Vettier, C. ; Kaldis, E. ; Karpinski, J. ; Rusiecki, S.
Amsterdam : ElsevierStaff ViewISSN: 0921-4526Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesRoessli, B. ; Allenspach, P. ; Fischer, P. ; Mesot, J. ; Staub, U. ; Maletta, H. ; Bruesch, P. ; Ritter, C. ; Hewat, A.W.
Amsterdam : ElsevierStaff ViewISSN: 0921-4526Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 0921-4526Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesFischer, P. ; Roessli, B. ; Mesot, J. ; Allenspach, P. ; Staub, U. ; Kaldis, E. ; Bucher, B. ; Karpinski, J. ; Hewat, A.W. ; Jilek, E. ; Rusiecki, S.
Amsterdam : ElsevierStaff ViewISSN: 0921-4526Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 0921-4534Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesMirmelstein, A. ; Podlesnyak, A. ; Voronin, V. ; Lebedev, S. ; Goshchitskii, B. ; Allenspach, P. ; Mesot, J. ; Staub, U. ; Furrer, A. ; Guillaume, M. ; Fischer, P.
Amsterdam : ElsevierStaff ViewISSN: 0921-4534Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 0921-4534Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesPodlesnyak, A. ; Kozhevnikov, V. ; Mirmelstein, A. ; Allenspach, P. ; Mesot, J. ; Staub, U. ; Furrer, A.
Amsterdam : ElsevierStaff ViewISSN: 0921-4534Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: PhysicsType of Medium: Electronic ResourceURL: