Dielectric and Mechanical Nonlinear Behavior of Mn Doped PMN-35PT Ceramics

Abstract

This paper presents an investigation on dielectric and mechanical nonlinear properties in Mn-doped PMN-35PT ceramics. The structural study of the ceramics verifies that the 1% mol Mn doped PMN-35PT is a pure perovskite phase with a tetragonal symmetry. SEM micrograph shows the same microstructural morphology of an undoped ceramic. From the EPR spectra, it has been concluded that the major part of Mn is present in Mn2+ rather than in Mn4+ form. The addition of Mn2+ ions acts on the dielectric, piezoelectric and mechanical properties by decreasing the relative dielectric permittivity (3800 to 2074), the dielectric losses (0.60 to 0.53), the piezoelectric coefficient d33 (650 to 403 pC/N), and increasing the mechanical quality factor Qm (78 to 317). It was found that in Mn2+ doped ceramics the dielectric response can not be described by Rayleigh law. This result can be understood taking into account that reversible motion of the domain wall is a relevant contribution to response of this material.