Zn-neighbor Cu NQR in Zn-substitutedYBa2Cu3O7

Abstract

We studied local electronic states near Zn in optimally doped YBa2(Cu1−xZnx)3O 7−δ and underdoped YBa2(Cu1−xZnx)4O8 via satellite signals of plane-site Cu(2) nuclear quadrupole resonance (NQR) spectra. From the relative intensity of Cu NQR spectra, the satellite signals are assigned to Zn-neighbor Cu NQR lines. The Cu nuclear spinlattice relaxation time of the satellite signal is shorter than that of the main signal, which indicates that the magnetic correlation is locally enhanced near Zn both for the underdoped and the optimally doped systems. The pure YBa2Cu4O8 is a stoichiometric, homogenous, underdoped electronic system; nevertheless, the Zn-induced inhomogeneous magnetic response in the CuO2 plane is more marked than that of the optimally doped YBa2Cu3O 7−δ . 74.25.Nf, 74.72.Bk

Comment on “Localized behavior near the Zn impurity inYBa2Cu4O8as measured by nuclear quadrupole resonance”

“…This line was discovered by Williams et al [2] and was confirmed by Itoh et al [3,4], while it is also possibly visible in an earlier report by Yamagata et al [5]. WK argue that this resonance arises from the four Cu first neighbors (Cu NN ) of each Zn impurity in CuO 2 planes.…”

“…We show here that the conclusions of WK cannot be sustained by their NQR measurements. Other comments on the work of WK, complementary those presented here, can be found in the comprehensive study of Itoh et al [4].…”

Vortex States of Tl2Ba2CuO6+δStudied via205Tl NMR at 2 Tesla

“…These results remind us of the in-plane impurity-substitution effect [17]. The nuclear moments close to an impurity show nonexponential relaxation, because of random impurity distribution.…”

Superconducting Fluctuation and Pseudogap in Disordered Short Coherence Length Superconductor

“…The pseudogap around the single impurity has been investigated by the NMR measurements. [64][65][66][67] We discuss the relevance of our results for these experiments. In this section, we adopt the self-consistent T-matrix approximation for N = 31 × 31 sites.…”