H. J. Silverstein, K. Fritsch, F. Flicker, A. M. Hallas, J. S. Gardner, Y. Qiu, G. Ehlers, A. T. Savici, Z. Yamani, K. A. Ross, B. D. Gaulin, M. J. P. Gingras, J. A. M. Paddison, K. Foyevtsova, R. Valenti, F. Hawthorne, C. R. Wiebe, H. D. Zhou
Solids can be classified into two general categories: (1) crystalline solids, which have a well-defined unit cell that translates in space, and (2) amorphous solids, or glasses, which are characterized by a lack of such long-ranged order. Such classification has been extended to magnetic systems, where spins residing on a lattice typically undergo long-ranged ordering below a transition temperature set by the magnitude of the relevant exchange interactions. However, frozen random spins on a lattice may fail to develop long-ranged order resulting in a magnetic, or spin, glass. The Hamiltonians for these spin glasses have two simple ingredients - explicit random chemical disorder and frustration. For years, physicists have searched for a material link between structural and spin glasses. While such systems have proved challenging to find, one example is Y2Mo2O7 - a solid with no explicit random disorder that displays spin glass behaviour. The nature of the spin-freezing, particularly whether or not it is intrinsic, has been a matter of debate for over three decades. Here, we report the first single crystal growth of this material. Through physical property measurements, scattering experiments, and theoretical modelling, we offer novel insight into the Y2Mo2O7 problem: for this unconventional spin glass, orbital effects should not be ignored.
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http://arxiv.org/abs/1305.1274
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