Hopping conduction and low-frequency dielectric relaxation in 5 mol % Mn doped (Pb,Sr)TiO3 films

The highly (00l)-oriented 5 mol % Mn doped Pb0.5Sr0.5TiO3 films with remarkable ferroelectric properties (2P(r)=27.1 mu C/cm(2) and 2E(c)=55.5 kV/cm) were fabricated on LaNiO3 coated silicon substrates by chemical solution deposition. The ac conductivity and the dielectric response of the films at various temperatures were studied. Hopping conduction accompanied by the dielectric relaxation at low frequencies was observed. The results can be correlated with the thermal-activated short range hopping of localized charge carriers through trap sites separated by potential barriers with different heights, i.e., localized electrons hopping between multivalence Mn sites (the activation energy of this hopping process is similar to 0.4 eV), which is also established in terms of the correlated barrier hopping model.