Coexistence of Antiferroelectric and Proton Glass States in Mixed K_0,26(NH₄)_0.74H₂PO₄Crystal Under Restricted Geometry Conditions

Abstract

The dielectric response of K 0,26 (NH 4 ) 0.74 H 2 PO 4 -SiO 2 composite prepared by embedding of corresponded salts into porous SiO 2 glass with 320 nm average pore diameter has been studied at the temperature range of 10-300 K. The transition from paraelectric to antiferroelectric (AFE) phase in implanted particles is detected at T N ≈ 45 K. Below ≈ 20 K the specific dispersion of dielectric response indicates a transition into proton glass (PG) state. It was found that the average time of dielectric relaxation follows the empirical Vogel-Fulcher law. Obtained results speak in favor of the coexistence of AFE and PG phases at low temperatures.