Distribution of Internal Random Fields in the Vicinity of Diffused Ferroelectric Phase Transition in K_0.81(NH₄)_0.19H₂PO₄ Single Crystal

Abstract

The analysis of P(E) hysteresis loops obtained near diffused ferroelectric phase transition in ferro-antiferroelectric K_0.81(NH₄)_0.19H₂PO₄ mixed crystal gave the possibility to estimate the shape of random fields distribution function. It was found that this function is well approximated by a sum of two Gaussians with positive and negative average values of internal field. Supposition is made that double-peak distribution of random fields is due to charges (probably Takagi defects) on boundaries between polar regions and nonpolar matrix.

Keywords:

• Single mixed crystal
• diffused ferroelectric phase transition
• random field distribution