Journal of Physical Studies 18(2/3), Article 2703 [7 pages] (2014) DOI: https://doi.org/10.30970/jps.18.2703 STATIC DIELECTRIC, PIEZOELECTRIC AND ELASTIC PROPERTIES OF ANTIFERROELECTRICS NH4H2PO4 AND NН4Н2AsO4 I. R. Zachek1, R. R. Levitskii2 1Lviv Polytechnic National University, 12, Bandery St., Lviv, UA--79013, Ukraine 2Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine 1, Svientsitskii St., Lviv, UA-79011, Ukraine

Within a modified proton ordering model of KH$_{2}$PO$_{4}$ family ferroactive compounds with taking into account linear on strains $ε_6 $ and $ε_4$ contributions to energy of proton system, but without taking into account tunneling, within the four-particle cluster approximation static dielectric, piezoelectric and elastic characteristics of NH$_4$H$_2$PO$_4$ type antiferroelectrics are studied and calculated. At the proper set of the parameters in paraelectric phase a good quantitative description of the corresponding experimental data for NH$_{4}$H$_{2}$PO$_{4}$ and NH$_{4}$H$_{2}$AsO$_{4}$ is obtained.

PACS number(s): 77.22.Ch, 77.65.Bn, 77.84.Fa, 77.80.$-$e

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