Abstract Measurements of the elastic energy dissipation coefficient and of the dynamic Young's modulus were performed on polycrystalline YBa2Cu3O7-x by the vibrating reed technique and torsional pendulum, in the frequency range 1-5000 Hz. The stoichiometry of the samples was varied in the range x = 0.02 - 0.7. From the isothermal modulus measurements a strong softening stage characterizing the onset of the ortho-tetragonal transformation was observed. The long time isotherms give an activation energy of 0.9 = 0.1 eV. Two relaxational damping peaks have been observed and attributed to the short range oxygen dynamics in the well oxygenated and oxygen deficient superconducting phases. On the basis of these results models for the structural transformation linked to oxygen out diffusion and for the oxygen dynamics in different stoichiometric conditions are discussed.
BONETTI, E., CAMMAROTA, G.P., CAMPARI, E.G., CASAGRANDE, A. (1993). The basal plane oxygen dependence of YBa2Cu3O7-x anelastic relaxation and orthorhombic to tetragonal phase transition [10.1051/jp4:19937324].
The basal plane oxygen dependence of YBa2Cu3O7-x anelastic relaxation and orthorhombic to tetragonal phase transition
BONETTI, E.
Primo
Conceptualization
;CAMMAROTA, G. P.Secondo
Formal Analysis
;CAMPARI, E. G.Penultimo
Investigation
;CASAGRANDE, A.Ultimo
Investigation
1993
Abstract
Abstract Measurements of the elastic energy dissipation coefficient and of the dynamic Young's modulus were performed on polycrystalline YBa2Cu3O7-x by the vibrating reed technique and torsional pendulum, in the frequency range 1-5000 Hz. The stoichiometry of the samples was varied in the range x = 0.02 - 0.7. From the isothermal modulus measurements a strong softening stage characterizing the onset of the ortho-tetragonal transformation was observed. The long time isotherms give an activation energy of 0.9 = 0.1 eV. Two relaxational damping peaks have been observed and attributed to the short range oxygen dynamics in the well oxygenated and oxygen deficient superconducting phases. On the basis of these results models for the structural transformation linked to oxygen out diffusion and for the oxygen dynamics in different stoichiometric conditions are discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
