Muon-spin-relaxation study of the Cu-spin dynamics in electron-doped high-T_c_ superconductor Pr_0.86_LaCe_0.14_Cu_1-y_Zn_y_O_4_

TL;DR

This study uses muon-spin-relaxation to explore how nonmagnetic Zn impurities affect Cu-spin dynamics in electron-doped high-T_c_ cuprates, revealing differences from hole-doped counterparts and suggesting the absence of dynamical stripe correlations.

Contribution

It provides new insights into impurity effects on Cu-spin fluctuations in electron-doped cuprates, highlighting differences from hole-doped systems and the role of Pr^3+^ moments.

Findings

No Zn-induced slowing down of Cu-spin fluctuations in electron-doped samples.

Fast muon spin depolarization below 100 K due to Pr^3+^ moments.

Differences from hole-doped cuprates suggest absence of dynamical stripe correlations.

Abstract

Muon-spin-relaxation (muSR) measurements have been performed for the partially Zn-substituted electron-doped high-T_c_ superconductor Pr_0.86_LaCe_0.14_Cu_1-y_Zn_y_O_4+alpha-delta_ with y=0-0.05 and the reduced oxygen content delta=0-0.09, in order to investigate nonmagnetic Zn-impurity effects on the Cu-spin dynamics. For all the measured samples with delta=0.01-0.09, it has been found that a fast depolarization of muon spins is observed below 100 K due to the effect of Pr^3+^ moments and that the muSR time spectrum in the long-time region above 5 mu-sec increases with decreasing temperature at low temperatures below 30 K possibly due to slowing down of the Cu-spin fluctuations assisted by Pr^3+^ moments. No Zn-induced slowing down of the Cu-spin fluctuations has been observed for moderately oxygen-reduced samples with delta=0.04-0.09, which is very different from the muSR results of La_2-x_Sr_x_Cu_1-y_Zn_y_O_4_. The possible reason may be that there are no dynamical stripe correlations of spins and electrons in the electron-doped high-T_c_ cuprates or that the effect of Pr^3+^ moments on the muSR spectra is stronger than that of a small amount of Zn impurities.