Dimensional Crossover of Vortex Dynamics Induced by Gd Substitution on Bi2212 Single Crystals

Abstract

The vortex dynamics of Bi${}_2$Sr${}_2$Ca${}_{1-x}$Gd${}_x$Cu${}_2$O${}_{8+\delta }$ single crystals is investigated by magnetic relaxation and hysteresis measurements. By substituting $Ca$ with $Gd$, it is found that the interlayer Josephson coupling is weakened and the anisotropy is increased, which leads to the change of vortex dynamics from 3D elastic to 2D plastic vortex creep. Moreover, the second magnetization peak, which can be observed in samples near the optimal doping, is absent in the strongly underdoped (with 2D vortex) region.

16 Pages, 6 Figures, To appear in Physica C

References in corpus (6)

• Elastic Theory of pinned flux lattices
• Phase diagrams of flux lattices with disorder
• Plastic vortex-creep in YBa${}_2$Cu${}_3$O${}_{7-x}$ crystals
• Abrupt Change of Josephson Plasma Frequency at the Phase Boundary of the Bragg Glass in Bi_2Sr_2CaCu_2O_{8+δ}
• Supercooling of the disordered vortex lattice in Bi_2Sr_2CaCu_2O_8+d
• Absence of Two-Dimensional Bragg Glasses