Curie-Weiss Behavior of Ferroelectric RbHSO4

Measurements of the dielectric constant of RbHSO 4 along the ferroelectric axis have been made for a well annealed specimen. The result indicates that, contrary to the previously reported results of the spontaneous polarization and the deuteron magnetic resonance in RbDSO 4 , the dielectric constant ε obeys a Curie-Weiss law of ε - ε 0 = C /( T - T 0 ) in 0.06°C< T - T 0 <20°C with ε 0 =4.7, C =144 K and T 0 =-7.9°C in agreement with the Landau type mean field theory.