Structural, dielectric and electrical properties of Sm-modified Pb(SnTi)O_3 ferroelectric system

摘要

We have synthesized (Pb_(1-x)Sm_x)(Sn_yTi_(1-y))_(1-x/4)O_3)(PSmST) polycrystalline ferroelectric ceramics with x = 0.05, 0.07, 0.1 and y = 0.45 by a solid-state reaction technique and performed preliminary X-ray diffraction (XRD) analysis, detailed temperature and frequency dependence dielectric measurements on them. The a.c. conductivity has been investigated over a wide range of temperature and the activation energy (E_(a.c.)) has also been calculated. It is observed that (i) the dielectric permittivity (epsilon) and loss tangent (tan delta) are dependent on frequency, (ii) the temperature of dielectric permittivity maximum shifts toward lower temperature side with the increase of samarium ion (Sm~(+3)) concentration at the Pb sites, and (iii) observed and calculated d-values of XRD patterns show that the compounds have been formed in orthorhombic single phase.