μSR study of the Cu-spin dynamics in the electron-doped high-Tc cuprate of Pr0.86LaCe0.14Cu1−(Zn,Ni) O4

Abstract

Effects of the Zn-and Ni-substitution on the Cu-spin dynamics in the electron-doped Pr 0.86 LaCe 0.14 Cu 1Ày (Zn,Ni) y O 4+aÀd with y ¼ 0, 0.01, 0.02, 0.05 and different values of the reduced oxygen content d have been studied using zero-field muon-spin-relaxation (mSR) measurements at temperatures down to 2 K. For the as-grown sample (d ¼ 0, y ¼ 0) and the sample with a very small d value (do0:01, y ¼ 0), a muon-spin precession due to long-range antiferromagnetic order has been observed. On the other hand, no precession has been observed for moderately oxygen-reduced samples (0.01pdp0.09). It has been found that for all the samples of 0.01pdp0.09 the asymmetry AðtÞ (mSR time spectrum) in the long-time region increases with decreasing temperature at low temperatures, suggesting possible slowing down of the Cu-spin fluctuations. On the other hand, no significant difference between Zn-and Ni-substitution effects on the slowing down of the Cu-spin fluctuations has been observed. r

Muon spin relaxation study of the Cu spin dynamics in electron-doped high-TcsuperconductorPr0.86LaCeRisdiana1, Adachi2, Oki3 et al. 2010Phys. Rev. BSelf Cite361250View full textAdd to dashboardCite

“…11 In this paper, we investigate Zn-impurity effects on the Cu-spin dynamics in the electron-doped high-T c superconductor Pr 0.86 LaCe 0.14 Cu 1−y Zn y O 4+␣−␦ with y = 0 -0.05 and the reduced oxygen content ␦ = 0 -0.09 from the ZF-and longitudinal-field ͑LF͒ SR measurements, in order to elucidate whether or not the concept of the pinning of the dynamical stripe correlations by Zn holds good in the electrondoped system. 12,13 …”

Enhancement of magnetism by tailoring synthesis conditions in electron-doped superconducting nanoparticles

“…Based on the previous reports, superconductivity occurs when the δ value is in the optimum range of about 0.040–0.090. 34 It indicates that the Eu 1.85 Ce 0.15 CuO 4+ α − δ nanoparticles are in the optimum range.…”

“…11,33 It is important to remove the possibility that the spin fluctuations cannot be observed due to bigger effects from the magnetic moment of the A site. 34 The Ce concentration of 0.15 is chosen because it is an optimum doped concentration where the critical temperature is at its maximum. 11,33 Thus, it is expected that the suppression of superconductivity can be clarified.…”

Structural Properties and Hopping Conduction in the Normal State of Electron-Doped Superconductor Cuprate Eu2–xCexCuO4+α–δ

“…Powder samples of the electron-doped superconducting cuprate of Eu 2– x Ce x CuO 4+α–δ were prepared by a solid-state reaction method. ,, The concentration of Ce ( x ) was set in the range between x = 0.10 and 0.20. All powder precursors of Eu 2 O 3 , CeO 2 , and CuO were weighed in certain stoichiometric ratios, pulverized, and prefired at 900 °C for 20 h. All of the prefired samples were reground and pressed into pellets with a diameter of 10 mm and then sintered at 1050 °C for 16 h. The samples obtained were referred to as-grown samples of Eu 2– x Ce x CuO 4+α , where α is the excess oxygen in the sample and is estimated to have a value much less than 1 (|α| ≪ 1) . Furthermore, to reduce the excess oxygen (α), the as-grown samples were annealed in an argon gas flow at various temperatures in the range of 900–930 °C for 10 to 20 h. − ,,, The value of δ was obtained from the weight change before and after the annealing process.…”