Effect of manganese doping on the electrical characteristics of sol-gel derived lead zirconate titanate thin films

Abstract

Manganese (Mn) doped Pb(Zr,Ti)O₃ thin films were prepared by sol-gel technique and their dielectric, ferroelectric and dc leakage current characteristics were studied in detail. There was a decrease in the dielectric constant, phase transition temperature and increase in the leakage current with the increase in the concentrations of the Mn ions. The decrease in the transition temperature is due to the breaking down of translation symmetry of the polarization, thereby establishing the local dipole moments on suppressing the long-range ferroelectric order. The dielectric dispersion was large for the higher concentration of Mn ions in PZT thin films at lower frequencies and is attributed to the space charge accumulation. The loss tangent initially increases and then decreases with the increase in the Mn ions concentrations indicating the disappearance of the conducting boundary layers. The undoped and Mn doped PZT thin films exhibit the hysteresis loops which confirms the ferroelectric behavior. The dc leakage current conduction mechanism obeyed to space charge limited mechanism and the activation energy calculated from the dc leakage current is attributed to shallow traps.