ABSTRACT Neutron-diffraction data collected under vacuum at 680 and 695 K have been compared with elastic energy dissipation and dynamic Young’s modulus measurements in YBa2Cu3O6+x. The orthorhombic to tetragonal phase transition has been observed in isothermal conditions. The data suggest that a phonon softening occurs at the oxygen disordering, which, in these experimental conditions, precedes the phase transition. The elastic energy dissipation presents a peak above room temperature. Its origin and behavior are discussed in terms of an oxygen atom repopulation model, with activation energy depending on the orthorhombic strain and oxygen ordering in the basal plane.
Isothermal phase transition and elastic energy dissipation inYBa2Cu3O6+x / Bonetti, E.; Campari, E. G.; D’Astuto, M.; Marangolo, M.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - STAMPA. - 51:2(1995), pp. 1249-1257. [10.1103/PhysRevB.51.1249]
Isothermal phase transition and elastic energy dissipation inYBa2Cu3O6+x
Campari, E. G.
Secondo
Formal Analysis
;Marangolo, M.Ultimo
Validation
1995
Abstract
ABSTRACT Neutron-diffraction data collected under vacuum at 680 and 695 K have been compared with elastic energy dissipation and dynamic Young’s modulus measurements in YBa2Cu3O6+x. The orthorhombic to tetragonal phase transition has been observed in isothermal conditions. The data suggest that a phonon softening occurs at the oxygen disordering, which, in these experimental conditions, precedes the phase transition. The elastic energy dissipation presents a peak above room temperature. Its origin and behavior are discussed in terms of an oxygen atom repopulation model, with activation energy depending on the orthorhombic strain and oxygen ordering in the basal plane.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
