Zobrazeno 1 - 10
of 427
pro vyhledávání: '"N Pyka"'
Autor:
P. Bourges, Matteo d'Astuto, M. Loewenhaupt, Alexandre Ivanov, N. Pyka, H. Casalta, D. Petitgrand, A. Metz
Publikováno v:
Physical Review B. 61:14311-14314
Model predictions for the Nd spin-wave dispersion in ${\mathrm{Nd}}_{2}{\mathrm{CuO}}_{4}$ have been tested with high-resolution inelastic neutron scattering on a single crystal at $T=0.5\mathrm{K}.$ A Heisenberg model in the random phase approximati
Publikováno v:
Physical Review B. 59:11020-11026
Autor:
Taku J. Sato, Stéphane Raymond, Hiroaki Kadowaki, Hironobu Fujii, G. Nakamoto, Yosikazu Isikawa, Toshiro Takabatake, N Pyka, G. Lapertot, Louis-Pierre Regnault, Jacques Flouquet
Publikováno v:
Journal of Physics: Condensed Matter. 9:1599-1608
We have used inelastic neutron scattering to determine the spin dynamics in the Kondo insulator CeNiSn under magnetic fields up to 10 T applied parallel to the easy a axis. The well known excitations peaked at meV located at the Brillouin zone centre
Publikováno v:
Physical Review B. 52:7230-7242
A common empirical model is developed for the lattice dynamics of the cuprates ${\mathrm{La}}_{2}$${\mathrm{CuO}}_{4}$, (La,Sr${)}_{2}$${\mathrm{CuO}}_{4}$, ${\mathrm{Nd}}_{2}$${\mathrm{CuO}}_{4}$, ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}
Publikováno v:
Solid State Ionics. 72:72-75
We have investigated the equilibrium defect structure of single crystalline nonstoichiometric iron doped nickel oxide, (Ni 1-x Fe x ) 1- δO (x=0.06), at high temperatures (1000-1250°c) and nonstoichiometries 0.004
Publikováno v:
Materials Science and Engineering: A. 177:55-61
The residual stress state of brazed ceramic-steel components was investigated by neutron diffraction experiments. In addition, X-ray residual stress measurements were performed at the surface of the specimens. The neutron data show clear evidence of
Autor:
G. Heger, Isao Tanaka, Zachary Fisk, Markus Braden, K. Gamayunov, N. Pyka, W. Schnelle, W. Schwarz, Hironao Kojima
Publikováno v:
Zeitschrift f�r Physik B Condensed Matter. 94:29-37
The phase transition from the tetragonal to the orthorhombic structure in La2−x Sr x CuO4+δ has been studied combining elastic and inelastic neutron scattering and specific heat measurements on the same well characterized crystals. This analysis f
Publikováno v:
Physical Review Letters. 70:1457-1460
Inelastic neutron scattering yielded the first information on superconductivity-induced frequency shifts for q¬=;0 phonons in YBa 2 Cu 3 O x . For branches starting from the Raman-active mode at 340 cm -1 (10.2 THz), the shifts were round to decreas
Autor:
Lothar Pintschovius, N. Pyka, P. Bourges, N. L. Mitrofanov, A.Yu. Rumiantsev, W. Reichardt, Alexandre Ivanov
Publikováno v:
Europhysics Letters (EPL). 18:711-716
We have found evidence for an incipient structural phase transformation in Nd2CuO4 by inelastic-neutron-scattering experiments. In this compound, Cu is square-planar coordinated by four O(1) ions which can rotate as a rigid entity around the 001-axis
Autor:
W. Reichardt, Gaston Collin, Ph. Bourges, Alexandre Ivanov, N. Pyka, N. L. Mitrofanov, Lothar Pintschovius, A.Yu. Rumiantsev
Publikováno v:
Physica C: Superconductivity
3RD INTERNATIONAL CONF ON MATERIALS AND MECHANISMS OF SUPERCONDUCTIVITY : HIGH TEMPERATURE SUPERCONDUCTORS
3RD INTERNATIONAL CONF ON MATERIALS AND MECHANISMS OF SUPERCONDUCTIVITY : HIGH TEMPERATURE SUPERCONDUCTORS, Jul 1991, KANAZAWA, JAPAN, Japan. pp.156-161, ⟨10.1016/0921-4534(91)91965-7⟩
3RD INTERNATIONAL CONF ON MATERIALS AND MECHANISMS OF SUPERCONDUCTIVITY : HIGH TEMPERATURE SUPERCONDUCTORS
3RD INTERNATIONAL CONF ON MATERIALS AND MECHANISMS OF SUPERCONDUCTIVITY : HIGH TEMPERATURE SUPERCONDUCTORS, Jul 1991, KANAZAWA, JAPAN, Japan. pp.156-161, ⟨10.1016/0921-4534(91)91965-7⟩
A survey is presented on recent progress in the understanding of the lattice dynamics in Nd2CuO4, (La,Sr)2CuO4 and YBa 2 Cu 3 O 6 7 . Classical anharmonicity and twinning were found to be major complications for the interpretation of the data. The la