Ferroelectric behavior of KH 2PO 4 in the critical region

Abstract

The temperature dependence of the hysteresis loops and the dielectric constant of KH 2PO 4 has been accurately determined in the neighborhood of the Curie temperature, T c . No evidence has been found of a discontinous jump (indicative of a 1st order transition) in the spontaneous polarization at T c . The critical exponents β = 0.50 ± 0.03, δ = 2.95 ± 0.10 and γ = 1.00 ± 0.05 have been determined. These values are closedto those found in other ferroelectric transitions (f.1. TGS) and are consistent with the mean field model predictions for the critical exponents.