title: Heat capacity study of relaxors BaTi(0.65)Zr(0.35)O(3) and BaTi(0.60)Zr(0.40)O(3).
abstract: The heat capacity of two relaxors BaTi(1-x)Zr(x)O(3) (x = 0.35,0.40) was measured using adiabatic calorimetry in the temperature range 100-360 K. The C(p)(T) dependence of both compositions is characterized by the presence of two diffuse anomalies near the Burns temperature T(d) and the temperature of the maximum in permittivity T(m) in the temperature ranges 250-350 K and 120-200 K. The anomalous heat capacity near T(d) was analysed taking into account the distribution of Zr concentration in nanoregions leading to the distribution of their transition temperatures into the polar phase. Excess heat capacity near T(m) was discussed in the framework of the spherical random bond-random field model. The results are compared with the data obtained by the same procedures for PbMg(1/3)Nb(2/3)O(3) studied experimentally earlier.
authors.affiliation: L V Kirensky Institute of Physics, Siberian Division, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russia.
authors.forename: Michail
authors.initials: M
authors.lastname: Gorev
authors.forename: Vitaly
authors.initials: V
authors.lastname: Bondarev
authors.forename: Philippe
authors.initials: P
authors.lastname: Sciau
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Savariault