Eur. Phys. J. B 10, 233-236 (1999)
https://doi.org/10.1007/s100510050850

Spin dynamics in hole-doped two-dimensional S = 1/2 Heisenberg antiferromagnets: ⁶³Cu NQR relaxation in La_2-xSr_xCuO₄ for x≤0.004

¹ Department of Physics "A. Volta", Unità INFM di Pavia, Via Bassi 6, 27100 Pavia, Italy
² Ames Laboratory-USDOE and Department of Physics and Astronomy, ISU, Ames, Iowa 50011, USA

Corresponding author: ^a carretta@pv.infn.it

Received: 13 August 1998
Revised: 7 December 1998
Published online: 15 July 1999

Abstract

The effects on the correlated Cu²⁺ S = 1/2 spin dynamics in the paramagnetic phase of La_2-xSr_xCuO₄ (for ) due to the injection of holes are studied by means of ⁶³Cu NQR spin-lattice relaxation time T₁ measurements. The results are discussed in the framework of the connection between T₁ and the in-plane magnetic correlation length . It is found that at high temperatures the system remains in the renormalized classical regime, with a spin stiffness constant reduced by small doping to an extent larger than the one due to Zn doping. For the effect of doping on appears to level off. The values for derived from T₁ for K are much larger than the ones estimated from the temperature behavior of sublattice magnetization in the ordered phase (). It is argued that these features are consistent with the hypothesis of formation of stripes of microsegregated holes.