The effect of multivalency manganese doping on the defect structure and enhanced electrical resistivity is studied for the high-temperature piezoelectric ($1-x$)BiScO${}_3$–$x$PbTiO${}_3$ (BSPT) solid-solution system by means of multifrequency electron paramagnetic resonance spectroscopy combined with conductivity measurements. The results show that manganese is rather incorporated on a scandium than a titanium site as an isovalent substitute (${\mathrm{Mn}}_{\mathrm{Sc}}^{\times }$) instead of acceptor-type centers, such as ${\mathrm{Mn}}_{\mathrm{Ti}}^{\prime }$, ${\mathrm{Mn}}_{\mathrm{Ti}}^{\prime \prime }$, or ${\mathrm{Mn}}_{\mathrm{Sc}}^{\prime }$. The enhanced electric resistivity is found being on the one hand due to the trapping of conduction electrons at the manganese functional center sites (${\mathrm{Mn}}_{\mathrm{Sc}}^{\times }+e^{\prime }{\mathrm{Mn}}_{\mathrm{Sc}}^{\prime }$). On the other hand, through the formation of ${({\mathrm{Mn}}_{\mathrm{Sc}}^{\prime }-V_{\mathrm{O}}^{••})}^{•}$ defect complexes the ionic conductivity is reduced. Concerning the overall mechanism of charge compensation in that material, both kinds of defects mutually compensate.

• Received 5 October 2010

DOI:https://doi.org/10.1103/PhysRevB.84.064113