We report muSR experiments on Mg{x}Cu{4-x}(OH)6Cl2 with x \sim 1, a new material isostructural to Herbertsmithite exhibiting regular kagome planes of spin 1/2 (Cu^{2+}), and therefore a candidate for a spin liquid ground state. We evidence the absence of any magnetic ordering down to 20 mK (\sim J/10^4). We investigate in detail the spin dynamics on well characterized samples in zero and applied longitudinal fields and propose a low T defect based interpretation to explain the unconventional dynamics observed in the quantum spin liquid phase.
@article{arxiv.1106.6309,
title = {Spin Liquid Ground State in the Frustrated Kagome Antiferromagnet MgCu3(OH)6Cl2},
author = {E. Kermarrec and P. Mendels and F. Bert and R. H. Colman and A. S. Wills and P. Strobel and P. Bonville and A. Hillier and A. Amato},
journal= {arXiv preprint arXiv:1106.6309},
year = {2014}
}