Vibrational and electronic anomalies near Tc in tetragonal superconducting YBa2(Cu0.9557Fe0.05)3O7.1

✍ Scribed by C.W. Kimball; J.L. Matykiewicz; Hsun Lee; John Giapintzakis; A.E. Dwight; B.D. Dunlap; James D. Jorgensen; B.W. Veal; F.Y. Fradin

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 542 KB
• Volume: 156
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(88)90019-6

✦ Synopsis

M~ssbauer effect studies have been made as a function of temperature for the orthorhombic (x= 0,01, 0.02 ) and tetragonal (x=0.05) superconducting compounds YBa2(Cu~_x57Fex)307+r For Fe in or slightly displaced from the Cul (000) site, temperature dependent measurements yield Debye temperatures for the Mtissbauer shift 0~ in the range of 601 to 698 K and for the resonant fraction Of in the range from 333 to 568 K, depending on the local oxygen configuration. Very little change is observed in the region of the superconducting transition Tc for the orthorhombic phase samples, but both phonon and electronic changes occur near T¢ in the tetragonal phase. The vibrational behavior of Fe in the Cul site shows a dramatic hardening near and below Tc in tetragonal YBa2 (Cuo.95Feo.o5)307. ~. The quadrupolar splitting EQ indicates a change in field gradient in this same temperature region. The M6ssbauer shift also behaves anomalously near To.