Anelastic spectroscopy in superconducting oxides

• Autor(a) principal: De Albuquerque Gimenez, Juliana Maria [UNESP]
• Data de Publicação: 2005
• Outros Autores: Grandini, Carlos Roberto [UNESP], Santos, Dayse Iara dos [UNESP], Da Cunha, Alfredo Gonçalves
• Tipo de documento: Artigo de conferência
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.4028/www.scientific.net/MSF.498-499.581; http://hdl.handle.net/11449/68604
• topic: BSCCO anelastic spectroscopy; Cuprates; Oxygen mobility; SBCO; Concentration (process); Heat treatment; Phase transitions; Relaxation processes; Spectroscopic analysis; Thermal effects; Superconducting materials

Since the discovery of the high Tc superconductors, several works have been made about the different properties of these materials. Anelastic spectroscopy experiments are sensitive tools to the study of defects in solids and phase transitions. By this technique, we can distinguish the different types of atomic jumps that happen to different temperatures. The intensity of the peaks in the anelastic spectrum and the step in the torsional modulus are related with the concentration of the relaxing entities, and the position of the peaks is determined by its mobility. In this paper, the study on Bi and Sm based superconducting oxides was made by anelastic relaxation measurements using a torsion pendulum. The samples were submitted to successive thermal treatments in high vacuum, in the temperature range between 100 K and 650 K, heating rate about 1 K/min. For Bi based superconducting oxides the results shown two peaks, that were associated to interstitial oxygen mobility and to orthorhombic to monoclinic phase transition. For Sm based superconducting oxides the results shown a relaxation peak that was attributed to the jumps of the oxygen atoms in the inter-chains O1 and 05 of the lattice.