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Article

Incommensurate instability and lattice dynamics of potassium selenate within a semiempirical rigid-ion model
(American Institute of Physics Publising LLC, 1990)
The lattice dynamics of potassium selenate is analyzed using a rigid-ion model with the selenate groups reduced to rigid bodies. The interatomic forces have been adjusted only using static structural data. The number of ...
Article

Comportamiento eléctrico de monocristales 4.7mol%Y-PSZ
(1998)
La función respuesta escalón de Kohlrausch-Williams-Watts ha permitido incorporar la contribución dieléctrica a la res-puesta eléctrica de los monocristales Y2O3 - Zr02. El modelo de divergencia infrarroja permite interpretar ...
Article

Optical phonons, crystal-field transitions, and europium luminescence-excitation processes in Eu2BaCoO5: Experiment and theory
(American Institute of Physics Publising LLC, 1994)
The Europium compound Eu2BaCoO5 has been studied by means of Raman and x-ray-absorption spectroscopies. The eigenfunctions and frequencies of the optical normal modes have been calculated from an adequate potential showing ...
Article

Low-frequency excitations in glassy selenium: A comparison of neutron-scattering and molecular-dynamics results
(American Institute of Physics Publising LLC, 1993)
The microscopic low-frequency dynamics of glassy selenium is investigated by means of the concurrent use of neutron inelastic scattering and computer simulations. A separation of the dynamic response in terms of intra- and ...
Article

Low-frequency excitations in a molecular glass: Single-particle dynamics
(American Institute of Physics Publising LLC, 1992)
The low-frequency dynamics of a molecular glass former has been investigated by means of inelastic neutron scattering from a mostly incoherent sample as well as by computer molecular-dynamics simulation. The mode assignments ...
Article

Correlated atomic motions in glassy selenium
(American Institute of Physics Publising LLC, 1994)
The elastic and total (energy-integrated) structure factors for glassy selenium have been measured by means of neutron spectroscopy within the temperature range 15 KT310 K. The correlated nature of the atomic vibrations ...
Article

Thermodynamic study of commensurate-incommensurate phase transitions in Rb2ZnCl4
(American Physical Society, 1999)
We have performed simultaneous measurements of heat capacity and dielectric constant on a high-quality single crystal of Rb2ZnCl4 near the commensurate-incommensurate transition area. Maximum heat capacity is found to be ...
Article

Evidence for a supercooled plastic-crystal phase in solid ethanol
(American Physical Society, 1996)
The existence of an orientationally disordered cubic phase of solid ethanol is revealed by x-ray diffraction and Raman spectroscopic measurements. Such a phase, whose existence was postulated some time ago on the basis of ...
Article

Microscopic dynamics of glycerol in its crystalline and glassy states
(American Physical Society, 1996)
The dynamics of crystalline glycerol are studied by means of Raman spectroscopy and lattice dynamics calculations employing a semiflexible model to represent the low-lying molecular vibrations. The latter is validated ...
Article

Ionic conductivity of ZrO2-12 mol% Y2O3 single crystals
(APS Physics, 1993)
Fast ionic conductors are important to study because of their use in the construction of technologically useful devices such as electrochemical cells, oxygen monitors, and the high-temperature fuel cell. Oxygen-ion conductors ...