Doping Dependence of Vortex Regimes in Y$_{1-x}$Pr$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-δ}$ Single Crystals

P. Gyawali; V. Sandu; B. J. Taylor; M. B. Maple; C. C. Almasan

doi:10.1103/PhysRevB.77.174504

paper

Doping Dependence of Vortex Regimes in Y $_{1 - x}$ Pr $_{x}$ Ba $_{2}$ Cu $_{3}$ O $_{7 - δ}$ Single Crystals

arXiv:0709.4267 · doi:10.1103/PhysRevB.77.174504

Abstract

Magnetic relaxation measurements on a series of Y $_{1 - x}$ Pr $_{x}$ Ba $_{2}$ Cu $_{3}$ O $_{7 - δ}$ ( $x = 0.13, 0.34, 0.47$ ) single crystals were performed over a large field and temperature range in order to investigate the characteristics of the vortex matter across the second magnetization peak (SMP). The magnitude of the SMP varies non-monotonically with the Pr concentration; i.e., the irreversible magnetization normalized by its value at the onset field $H_{o n}$ displays a maximum for the $x = 0.34$ single crystal. The two characteristic fields, $H_{o n}$ and $H_{s p}$ , follow different temperature $T$ dependences: $H_{o n} \propto T^{ν_{o n}}$ and $H_{s p} \propto [1 - (T / T_{c})^{2}]^{ν_{s p}}$ . The extracted values of the apparent activation energy $U^{*}$ and the creep exponent $μ$ display a maximum at a field $H_{o n} < H^{*} < H_{s p}$ . Their field dependences point toward the coexistence of both elastic and plastic creep for $H > H_{o n}$ . The degree of participation of each creep mechanism is determined by the charge carrier density, which controls both the elastic properties of the vortex matter and the pinning potential.

arXiv comment7 figures

Doping Dependence of Vortex Regimes in Y1−x​Prx​Ba2​Cu3​O7−δ​ Single Crystals

Abstract

References in corpus (19)

Doping Dependence of Vortex Regimes in Y $_{1 - x}$ Pr $_{x}$ Ba $_{2}$ Cu $_{3}$ O $_{7 - δ}$ Single Crystals