The geometrically-frustrated spin glass Y2Mo2O7 has been considered widely to be crystallographically ordered with a unique nearest neighbor magnetic exchange interaction, J. To test this assertion, we present x-ray-absorption fine-structure results for the Mo and Y K edges as a function of temperature and compare them to results from a well-ordered pyrochlore, Tl2Mn2O7. We find that the Mo-Mo pair distances are significantly disordered at approximately right angles to the Y-Mo pairs. These results strongly suggest that lattice disorder nucleates the spin-glass phase in this material.
@article{arxiv.cond-mat/0005316,
title = {Local lattice disorder in the geometrically-frustrated spin glass pyrochlore Y2Mo2O7},
author = {C. H. Booth and J. S. Gardner and G. H. Kwei and R. H. Heffner and F. Bridges and M. A. Subramanian},
journal= {arXiv preprint arXiv:cond-mat/0005316},
year = {2009}
}