By means of neutron scattering techniques we have investigated the frustrated pyrochlore magnet Ho_2Sn_2O_7, which was found to show a ferromagnetic spin-ice behavior below T \simeq 1.4 K by susceptibility measurements. High-resolution powder-neutron-diffraction shows no detectable disorder of the lattice, which implies appearance of a random magnetic state solely by frustrated geometry, i.e., the corner sharing tetrahedra. Magnetic inelastic-scattering spectra show that Ho magnetic moments behave as an Ising spin system at low temperatures, and that the spin fluctuation has static character. The system remains in a short-range ordered state down to T = 0.4 K. By analyzing the wave-number dependence of the magnetic scattering using a mean field theory, it is clarified that the Ising spins interact via the dipolar interaction. Therefore we conclude that Ho_2Sn_2O_7 belongs to the dipolar-spin-ice family. Slow spin dynamics is exhibited as thermal hysteresis and time dependence of the magnetic scattering.
@article{arxiv.cond-mat/0107278,
title = {Neutron scattering study of dipolar spin ice Ho_2Sn_2O_7: Frustrated pyrochlore magnet},
author = {Hiroaki Kadowaki and Yoshinobu Ishii and Kazuyuki Matsuhira and Yukio Hinatsu},
journal= {arXiv preprint arXiv:cond-mat/0107278},
year = {2007}
}