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.

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

Abstract

References in corpus (3)

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