Transition to long-range magnetic order in the highly frustrated insulating pyrochlore antiferromagnet Gd2Ti2O7

Experimental evidence from measurements of the ac and dc susceptibility, and heat-capacity data show that the pyrochlore structure oxide, Gd2Ti2O7, exhibits short-range order that starts developing at 30 K, as well as long-range magnetic order at T∼1 K. The Curie-Weiss temperature, θCW=-9.6 K, is largely due to exchange interactions. Deviations from the Curie-Weiss law occur below ∼10 K while magnetic heat-capacity contributions are found at …