Low-temperature magnetic properties of pyrochlore stannates

We report the magnetic properties of pyrochlore rare earth oxides R2Sn2O7 (R=Pr, Nd, Gd, Tb, Dy, Ho, Er, Tin and Yb). The magnetic susceptibility has been measured at temperatures down to 0.1 K, Among them, some compounds show the magnetic anomaly below 1 K. Nd2Sn2O7 and Gd2Sn2O7 show an antiferromagnetic ordering at 0.9 K and 1.0 K. respectively. Tb2Sn2O7 shows a ferromagnetic ordering at 0.87 K. Although both Er3+ and Yb3+ are a Kramers ion, no magnetic anomaly is observed at least down to 0.15 K. We found that Dy2Sn2O7 and Ho2Sn2O7 show 'spin ice' behavior. In addition, it is suggested that Pr2Sn2O7 is a new spin ice compound.