Title: ISOTOPIC EFFECTS IN PARTIALLY DEUTERATED PIEZOELECTRIC CRYSTALS OF ROCHELLE SALT
Authors: R.R.Levitskii (Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine) , I.R.Zachek (State University ``Lvivs'ka Politekhnika'', 12 Bandera Str., 79013, Lviv, Ukraine) , A.P.Moina, A.Ya.Andrusyk (Institute for Condensed Matter Physics, National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine)

We develop a theory for dielectric, piezoelectric, and elastic properties of partially deuterated (quenched disorder) crystals of Rochelle salt with taking into account the piezoelectric coupling. Results of numerical calculations are presented for a completely deuterated Rochelle salt and compared with available experimental data. Isotopic effect is explored within the mean crystal approximation, as well as within the developed theory using different trial sets of the fitting parameters. Theory predictions are given for the temperature and composition dependences of the calculated characteristics for partially deuterated crystals.

Key words: Rochelle salt, deuteration, piezoelectric effect
PACS: 77.22.Gm, 77.65.Bn, 77.80.Bh