Vortex Dynamics and Phase Diagram in the Electron Doped Cuprate Superconductor Pr$_{0.87}$LaCe$_{0.13}$CuO$_4$

Abstract

Second magnetization peak (SMP) in hole-doped cuprates and iron pnictide superconductors has been widely explored. However, similar feature in the family of electron-doped cuprates is not common. Here, we report the vortex dynamics study in the single crystal of an electron-doped cuprate Pr0.87LaCe0.13CuO4 superconductor using dc magnetization measurements. A SMP feature in the isothermal M (H) was observed for H ab-planes. On the other hand, no such feature was observed for H c-axis in the crystal. Using magnetic relaxation data, a detailed analysis of activation pinning energy via collective creep theory suggests an elastic to plastic creep crossover across the SMP. Moreover, for H ab, a peak in the temperature dependence of critical current density is also observed near 7 K, which is likely be related to a dimensional crossover (3D-2D) associated to the emergence of Josephson vortices at low temperatures. The anisotropy parameter obtained γ ≈ 8-11 indicates the 3D nature of vortex lattice mainly for H c-axis. The H-T phase diagrams for H c and H ab are presented.