Abstract Dynamic Young's modulus measurements, have been performed by the vibrating reed technique (102–104 Hz) on polycrystalline YBa2Cu3O7−x samples in the temperature range 300–900 K. A strong modulus softening, indicative of a phase transition, is measured at about x = 0.45. DTG measurements versus temperatures show in correspondence a maximum in the oxygen desorption rate. Long time modulus isotherms display an exponential trend linked to a thermally activated structural process with activation energy H = 0.9 ± 0.1 eV. On the basis of the experimental results a model for the structural transformation linked to the twinned interfaces mobility and to oxygen diffusion is presented and discussed.
Orthorhombic to tetragonal phase transition in YBa2Cu3O7−x observed by dynamic Young's modulus measurements / Bonetti, E.; Campari, E.G.; Manfredini, T.; Mantovani, S.. - In: PHYSICA. C, SUPERCONDUCTIVITY. - ISSN 0921-4534. - STAMPA. - 179:4-6(1991), pp. 381-386. [10.1016/0921-4534(91)92186-F]
Orthorhombic to tetragonal phase transition in YBa2Cu3O7−x observed by dynamic Young's modulus measurements
Campari, E. G.Secondo
Investigation
;
1991
Abstract
Abstract Dynamic Young's modulus measurements, have been performed by the vibrating reed technique (102–104 Hz) on polycrystalline YBa2Cu3O7−x samples in the temperature range 300–900 K. A strong modulus softening, indicative of a phase transition, is measured at about x = 0.45. DTG measurements versus temperatures show in correspondence a maximum in the oxygen desorption rate. Long time modulus isotherms display an exponential trend linked to a thermally activated structural process with activation energy H = 0.9 ± 0.1 eV. On the basis of the experimental results a model for the structural transformation linked to the twinned interfaces mobility and to oxygen diffusion is presented and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
