IMPROVEMENT OF REMANENT POLARIZATION STABILITY IN VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE COPOLYMERS

The P(VDF/TrFE) (VDF/TrFE=72/28, PIEZOTECH, France) films were prepare d by casting a methvethvlketone (MEK) solution on glass substrate and polarized by using different methods. The surface potential decay of P (VDF/ TrFE) films as a function of polarizing temperature was measured . Mean charge depths including space and dipole charges along the thic kness of the films were investigated by thermal pulse technique. The r emanent polarization in P(VDF/ TrFE) was stabilized by trapping space charges on or near the free surface in a double-layered him. The influ ence of space charge layer near the free surface on the remanent polar ization was studied by means of isothermal surface potential decay mea surement and TSD (Thermally Stimulated Discharge) experiment.