Phase formation and superconductivity studies on the LnBa2Cu3−xTixO7+δ (Ln = La-Gd, Y) system

✍ Scribed by T.A. Mary; U.V. Varadaraju

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 605 KB
• Volume: 215
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90225-f

✦ Synopsis

Substitution of Ti at a Cu-site in the LnBa2Cu3_xTixOT+6 (Ln = Nd,Sm) system reveals single phase formation up to x= 0.3. The LnBa2Cu2TiO7+6 phases are predominantly single phases for Ln=La-,Sm. Systematic studies of the LnBa2Cu3_xTixOT+6 (Ln = Nd,Sm ) system reveal an O-T transition at x = 0.1. The oxygen content of the phases increases to ~ 7.50 as x approaches 1.0. Electrical resistivity and AC magnetic susceptibility studies show that the superconducting transition temperature (To) decreases monotonically as a function of Ti content. The initial rate of decrease of Tc is ~ 15 K/at.% for Ln = Nd and ~ 13 K/at.% for Ln=Sm. Tc vanished for x>0.3 for the Nd-123 and x>0.4 for the Sm-123 phases. The phases with x>0.5 show semiconducting behaviour.