Absence of static magnetic order in lightly-doped Ti1-xScxOCl down to   1.7 K
  Impurity-induced magnetic order has been observed in many quasi-1D systems including doped variants of the spin-Peierls system CuGeO3. TiOCl is another quasi-1D quantum magnet with a spin-Peierls ground state, and the magnetic Ti sites of this system can be doped with non-magnetic Sc. To investigate the role of non-magnetic impurities in this system, we have performed both zero field and longitudinal field muSR experiments on polycrystalline Ti1-xScxOCl samples with x = 0, 0.01, and 0.03. We verified that TiOCl has a non-magnetic ground state, and we found no evidence for spin freezing or magnetic ordering in the lightly-doped Sc samples down to 1.7 K. Our results instead suggest that these systems remain non-magnetic up to the x = 0.03 Sc doping level. 
A.A. Aczel, G.J. MacDougall, F.L. Ning, J.A. Rodriguez, S.R. Saha,   F.C. Chou, T. Imai, and G.M. Luke
cond-mat.str-el