A Raman study of the structural properties of YBa2(Cu1 − xFex)3Oy

✍ Scribed by E. Liarokapis; L.T. Wille; Th. Leventouri; L. Martinez; H. Lu; V. Hadjiev; M. Iliev

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 697 KB
• Volume: 170
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(90)90010-c

✦ Synopsis

The effects of Fe-substitution on YBazCusO, have been investigated by means of Raman scattering, X-ray diffraction, resistivity and susceptibility measurements. A series of samples of YBaz (Cu, ._zex) so, with different dopant concentration (0 d xb 0.15 ) has been prepared in two batches, the second set having undergone twice the heat and mechanical treatment used to produce the first batch. Considerable improvement in the superconducting transition temperature, T,. is obtained upon reprocessing. A phase transformation from orthorhombic to tetragonal symmetry is observed for x> 0.05 from the X-ray measurements in agreement with previous work. Using a micro-Raman technique, all five 4 vibrational modes have been measured and their dependence on Fe-concentration is analyzed. There are indications that iron substitutes for copper at both sites and that the structure is a mixture of orthorhombic and tetragonal microdomains for all x.