Structural study on high-pressure synthesized PbSrCaCuO system

✍ Scribed by X.-J. Wu; T. Tamura; S. Adachi; C.-Q. Jin; T. Tatsuki; H. Yamauchi

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 499 KB
• Volume: 247
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(95)00175-1

✦ Synopsis

In high-pressure synthesized Pb-Sr-Ca-Cu-O samples, critical temperatures (T c) of about 115 K and 70 K are reported by Yamauchi et al. [Jpn. J. Appl. Phys., to be published]. In these samples two phases with primitive fundamental unit cell have been identified by electron-diffraction (ED) and X-ray diffraction (XRD) analyses. The lattice parameters of the fundamental structure are a2o = 3.81, b2o = 3.83 and C2o = 12.10 ,A, for the "Pb"-1212 phase, and a3o ~ b3o = 3.82, C3o = 15.3 ,A, for the "Pb"-1223 phase, respectively. EDX analysis indicated that the crystals are Sr, Cu rich, and Pb, Ca poor. Superstructures were observed with superlattice parameters a2s = 4a20, b2s = b2o and c2~ = 2C2o for "Pb"-1212, and a3s = 3.1a30 , b3s = b30 and c3s = 2C3o for "Pb"-1223. Based on a HRTEM observation as well as a simulation, the model of the superstructure was constructed.