Phase diagram and dielectric properties of mixed Cs1-x(NH4)(x)H2PO4 crystals

• Author(s): Baranov, A. I. ; Dolbinina, V. V. ; Lanceros-Méndez, S. ; Schmidt, V. H.
• Date: 2002
• Persistent ID: http://hdl.handle.net/1822/4359
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): KDP; CDP; Mixed crystals; Dielectric; Quasi-one-dimensional
• Document Type: Article
• Language: Portuguese

Description

Influence of NH4-->Cs substitution has been studied in the mixed Cs1-x(NH4)(x)H2PO4 crystals system by means of dielectric measurements. The x-T phase diagram was determined: for ammonium concentrations up to 0.1 the system has a monoclinic paraelectric phase with a transition into a ferroelectric phase whose temperature increases with increasing ammonium concentration. For ammonium concentration 0.4 to 1.0 the system shows a tetragonal paraelectric phase and a transition into an antiferroelectric phase. No solid solutions with concentrations between 0.1 and 0.4 could be grown. The system was further studied with the quasi-one-dimensional Ising model and the three-dimensional anisotropic Ising model