Giant pyroelectric coefficient of Mn-doped PLT thin films epitaxially grown on (001) Pt/MgO

The c-axis-oriented epitaxial thin films of Mn-doped Pb1−xLaxTi1−x/4O3 (PLT) on (001) Pt/MgO substrates were prepared by rf-magnetron sputtering. To investigate the effect of the doped ion, 0–1.7 mol% MnO2 added to the PLT target powder. The temperature dependence of the relative dielectric constant ɛr measurements and modified Curie–Weiss plots suggested that the increasing of diffuseness n was induced by high-La substitution and the diffuseness n of PLT thin films decreased by the addition of Mn, considerably. Inner stress and thermodynamic analysis were carried out and the results propose that the increasing of γ with Mn doping caused by increasing the misfit strain of the c-axis-oriented epitaxial PLT thin films and substrate. As a result, giant pyroelectric coefficient (γ = 15.8 × 10−8 C/cm2 K) of Mn-doped epitaxial PLT thin film was achieved.