  We report systematic low temperature measurements of the DC magnetization, AC
susceptibility, and heat capacity of dysprosium pyrogermanate (Dy2Ge2O7) single
crystal and powder samples. Our results confirm that Dy2Ge2O7 is an anisotropic
antiferromagnet. The isothermal field dependent magnetization and the
integrated magnetic entropy both indicate that the Dy3+ ions behave as
Ising-like spins, analogous to those in the pyrochlore spin ice materials. Both
single-spin and collective spin relaxation phenomena appear to lead to spin
freezing in this material, again in analogy to observations in the spin ice
materials, suggesting that such phenomena may be generic to a broader class of
magnetic materials.
