Superconductivity and magnetism of Bi2Sr2CaCu2Ox Effect of quenching and pulverization

✍ Scribed by T. Ishida; K. Koga; S. Nakamura; Y. Iye; K. Kanoda; S. Okui; T. Takahashi; T. Oashi; K. Kumagai

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 972 KB
• Volume: 176
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(91)90690-z

✦ Synopsis

The effect of quenching on Bi,Sr&aCu,O, (BSCCO) has been investigated. Quenching enhances the critical temperature r,. The hole concentration nh ( w 5 x 102' cmm3) decreases as the quenching temperature Tq increases. The normal-state static susceptibility x,,c ( w 5 x lo-' emu/g) of the BSCCO pellet is almost independent of temperature but its magnitude decreases with the increase of TV Thermogravimetry (TG) analysis shows that the change in the oxygen content is very small when the sample is heated. The Cu nuclear quadrupole resonance (NQR) spectra are very broad. In addition, we have observed a large Curie-Weiss term in xDc and xEsR of powdered samples. From the Curie constant, the number of localized Cu'+ spins is estimated to reach 30% of total Cu atoms. This component almost disappears by re-annealing. In all cases, xEsR has almost the same magnitude as xoc, in marked contrast with YBazCu30,-+ The origin of the normal-state susceptibility is discussed.