Measurements of magnetic susceptibility, heat capacity and thermal expansion are reported for single crystalline CuSb2O6 in the temperature range 5<T<350 K. The magnetic susceptibility exhibits a broad peak centered near 60 K that is typical of one-dimensional antiferromagnetic compounds. Long-range antiferromagnetic order at TN = 8.7 K is accompanied by an energy gap (Δ = 17.48(6) K). This transition represents a crossover from one- to three-dimensional antiferromagnetic behavior. Both heat capacity and the thermal expansion coefficients exhibit distinct jumps at TN, which are similar to those observed at the normal-superconducting phase transition in a superconductor. This behavior is quite unusual, and is presumably associated with a Spin-Peierls transition occurring as a result of three-dimensional phonons coupling with {\it Jordan-Wigner-transformed} Fermions.
@article{arxiv.1306.3961,
title = {Transition from one-dimensional antiferromagnetism to three-dimensional antiferromagnetic order in single-crystalline CuSb$_{2}$O$_{6}$},
author = {A. Rebello and M. G. Smith and J. J. Neumeier and B. D. White and Yi-Kuo Yu},
journal= {arXiv preprint arXiv:1306.3961},
year = {2015}
}