Pyroelectric properties and electrical conductivity in samarium doped BiFeO3 ceramics

Highlights: ► Fabrication of Sm-doped BiFeO3 (BFO) ceramics using a modified solid-state reaction method was reported. ► The structural, electrical and pyroelectrical properties of the Sm-doped BFO were characterized. ► The effects of the Sm-dopant on the pyroelectric as well as electrical properties of BFO were revealed. ► The magnetic Néel temperature decreased with increasing Sm3+ doping level. - Abstract: Samarium (Sm3+) doped BiFeO3 (BFO) ceramics were prepared by a modified solid-state-reaction method which adopted a rapid heating as well as cooling during the sintering process. The pyroelectric coefficient increased from 93 to 137 μC/m2 K as the Sm3+ doping level increased from 1 mol% to 8 mol%. Temperature dependence of the pyroelectric coefficient showed an abrupt decrease above 80 °C in all samples, which was associated with the increase of electrical conductivity with temperature. This electrical conduction was attributed to oxygen vacancy existing in the samples. An activation energy of ∼0.7 eV for the conduction process was found to be irrespective of the Sm3+ doping level. On the other hand, the magnetic Néel temperature (TN) decreased with increasing Sm3+ doping level. On the basis of our results, the effects of Sm doping level on the pyroelectric and electrical properties of the BFO were revealed.