Systematic Cu-63 NQR studies of the stripe phase in La(1.6-x)Nd(0.4)Sr(x)CuO(4) for 0.07 <= x <= 0.25

TL;DR

This study uses Cu-63 NQR to investigate charge-stripe order in La(1.6-x)Nd(0.4)Sr(x)CuO(4), revealing bulk stripe order across a range of doping levels and highlighting x=1/8 as optimal for stripe formation.

Contribution

It systematically demonstrates bulk charge-stripe order in superconducting La(1.6-x)Nd(0.4)Sr(x)CuO(4) using NQR, correlating wipeout fraction with stripe order parameter.

Findings

Charge-stripe order causes NQR intensity wipeout below T(charge).

Stripe order is present throughout the superconducting doping range.

Optimal stripe formation occurs at x=1/8 doping.

Abstract

We demonstrate that the integrated intensity of Cu-63 nuclear quadrupole resonance (NQR) in La(1.6-x)Nd(0.4)Sr(x)CuO(4) decreases dramatically below the charge-stripe ordering temperature T(charge). Comparison with neutron and X-ray scattering indicates that the wipeout fraction F(T) (i.e. the missing fraction of the integrated intensity of the NQR signal) represents the charge-stripe order parameter. The systematic study reveals bulk charge-stripe order throughout the superconducting region 0.07 <= x <= 0.25. As a function of the reduced temperature t = T/T(charge), the temperature dependence of F(t) is sharpest for the hole concentration x=1/8, indicating that x=1/8 is the optimum concentration for stripe formation.