We present data on the magnetic properties of two classes of layered spin S=1/2 antiferromagnetic quasi-triangular lattice materials: Cu2(1−x)Zn2x(OH)3NO3 (0<x<0.65) and its long chain organic derivatives Cu2(1−x)Zn2x(OH)3(C7H15COO)⋅mH2O (0<x<0.29), where non-magnetic Zn substitutes Cu isostructurally. It is found that the long-chain compounds, even in a clean system in the absence of dilution, x=0, show spin-glass behavior, as evidenced by DC and AC susceptibility, and by time dependent magnetization measurements. A striking feature is the observation of a sharp crossover between two successive power law regimes in the DC susceptibility above the freezing temperature. Specific heat data are consistent with a conventional phase transition in the unintercalated compounds, and glassy behavior in the long chain compunds.
@article{arxiv.1007.0442,
title = {Spin glassiness and power law scaling in a quasi-triangular spin-1/2 compound},
author = {Jian Wu and Julia S. Wildeboer and Fletcher Werner and Alexander Seidel and Z. Nussinov and S. A. Solin},
journal= {arXiv preprint arXiv:1007.0442},
year = {2011}
}