Coincidence of vortex-lattice melting and loss of vortex correlation along the c direction in untwinned YBa2Cu3O7−δ Single Crystals

LÓPEZ, D.; RIGHI, E.F.; NIEVA, G.; DE LA CRUZ, F.

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Año: 1996 vol. 76 p. 4034 - 4037

0031-9007

We report on transport measurements using the dc flux transformer configuration in clean and twinned single crystals of YBa2Cu3O7−δ. We show that correlated disorder changes not only the order of the solid-liquid phase transition but also the nature of the vortices in the liquid state. In clean crystals, melting is shown to take place between a solid of vortex lines and a liquid with no correlation in the direction of the magnetic field. © 1996 The American Physical Society.