Dielectric and thermal properties of Pb2Nb2O7 at low temperature

Measurements of the dielectric constant, polarization, zero-field specific heat, and field-dependent specific heat of polycrystalline Pb2Nb2O7 at low temperatures are reported. No evidence for a phase transition at 15 K was found, contrary to previous suggestions of an antiferroelectric transition at 15 K based on dielectric data. The peak in the dielectric constant appears to be due to relaxation phenomena.