Vortex phase diagram in impurity doped YBa2Cu3Oy single crystals

✍ Scribed by Terukazu Nishizaki; Masataka Maeda; Takanori Sato; Norio Kobayashi

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 558 KB
• Volume: 426-431
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2005.02.016

✦ Synopsis

Impurity substituted single crystals of untwinned YBa 2 (Cu 1Àx M x ) 3 O 6.95 (M = Zn, Ni) have been prepared and the Zn and Ni substitution effect on the vortex phase diagram has been studied as a function of impurity concentration x. In YBa 2 (Cu 1Àx M x ) 3 O 6.95 with small amount of impurity [x (Zn) = 0.0003 (T c = 91 K), x (Ni) = 0.003 (T c = 90.5 K)], although the first-order vortex lattice melting transition H m (T) disappears, the order-disorder transition line H*(T) between the Bragg glass and the vortex glass phases has been observed. The obtained results suggest that Zn and Ni impurities strongly affect the vortex system in comparison with the oxygen vacancy in pure YBa 2 Cu 3 O y .