Thermal history-dependent superconductivity and local structure in La2CuO4+δ

✍ Scribed by E.T. Ahrens; A.P. Reyes; P.C. Hammel; J.D. Thompson; P.C. Canfield; Z. Fisk; J.E. Schirber

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 407 KB
• Volume: 212
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90595-h

✦ Synopsis

DC magnetic susceptibility measurements reveal a dependence of the superconducting critical temperature (To) on the cooling rate (R) in super-oxygenated LaECuO4+~. Bulk T0s vary by ~ 4 K depending on whether the sample is "'quenched" or slow cooled through a narrow temperature range around 195 +_ l0 K. 139La nuclear quadrupole resonance spectroscopy (NQR) shows the appearance of a feature indicating a distribution of local structures in the metallic phase below ~ 195 K, the same temperature regime where R is critical for T¢. The spectral weight associated with the metallic phase appears to increase for rapid cooling.