Magnetic susceptibility and specific heat studies of a geometrically frustrated pyrochlore antiferromagnet Tb2Nb2O7

Abstract We report here results of DC and AC magnetization, and magnetic specific heat measurements of a geometrically frustrated pyrochlore Tb 2 Nb 2 O 7 . The DC susceptibility χ is consistent with collective paramagnetism down to a temperature scale set by effective nearest-neighbor interactions, J eff ≈–1.5 K. However, AC susceptibility χ ac peak exhibits a frequency-dependence at T f ∼0.8 K, signaling a spin-glass-like freezing of Tb 3+ spins in Tb 2 Nb 2 O 7 .