Investigation of the Low-Temperature Spin-Liquid Behavior of the Frustrated Magnet Gadolinium Gallium Garnet

We report the results of powder neutron scattering measurements on the magnetic correlations in the frustrated antiferromagnet Gd₃Ga₅O₁₂. A clear view of the short-range magnetic order has been obtained for a temperature range 0.14--5 K. At T~0.14K there is a partial transition to a phase with a much longer correlation length. We argue that the low-temperature phase is not an ordinary spin glass, as was suggested by bulk properties measurements, but rather a mixture of a spin-liquid state with a set of rigid magnetic pieces nucleated around impurity centers. The experimental data are compared with the results of Monte Carlo simulations performed for several models.