Critical behavior of the specific heat of dysprosium near the néel temperature

The heat capacity has been measured in Dy near its Néel temperature. Careful analysis of the data shows an apparent change in the sign of the exponent α at t_d ～ 0.005. The outer region behaves universally with ? = 1, n = 2 systems, having α = α′ = ? 0.02 ± 0.01, and the inner region has α = α′ = + 0.18 ± 0.08, in agreement with predictions for anisotropic dipolar-dominated systems.