Oxygen mobility and structural phase transformation in Bi2Sr2CaCu2O8+δ measured by anelastic spectroscopy

✍ Scribed by Juliana Maria de Albuquerque Gimenez; Carlos Roberto Grandini; Dayse Iara dos Santos

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 434 KB
• Volume: 408-410
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2004.03.074

✦ Synopsis

One of the most studied ceramic superconductors for application has been, undoubtedly, Bi 2 Sr 2 CaCu 2 O 8þd . Although being a multiphasic material, it has proved to have great advantages compared to other ceramic systems. Measurements of the elastic energy loss and modulus (anelastic spectroscopy) as a function of temperature can distinguish among different atomic jumps that occur inside the various phases or at different local ordering. In this paper, mechanical loss spectra of Bi 2 Sr 2 CaCu 2 O 8þd bar shaped samples, made by a conventional method, have been measured between 80 and 600 K, using a torsion pendulum operating in frequencies below 50 Hz, for samples annealed in vacuum up to 600 K. Possible relaxation mechanisms are proposed to explain the origin of the mechanical-loss peaks observed 300 and 500 K.