Abstract
We investigate the Néel temperature of as a function of the site dilution at the sites with , utilizing the muon spin relaxation technique. The Néel temperature, which is for the undoped system, becomes significantly reduced for less than one percent of doping , giving a support for the previous proposal for the good one-dimensionality. The concentration dependence of the Néel temperature is compared with a recent theoretical study [S. Eggert, I. Affleck, and M. D. P. Horton, Phys. Rev. Lett. 89, 47 202 (2002)] of weakly coupled one-dimensional antiferromagnetic chains of spins, and a quantitative agreement is found. The inhomogeneity of the ordered moment sizes is characterized by the SR time spectra. We propose a model that the ordered moment size recovers away from the dopant sites with a recovery length of sites. The origin of the finite recovery length for the gapless antiferromagnetic chain is compared to the estimate based on the effective staggered magnetic field from the neighboring chains.
2 More- Received 6 March 2004
DOI:https://doi.org/10.1103/PhysRevB.70.094402
©2004 American Physical Society