Pyroelectric properties and electrical conductivity in samarium doped BiFeO3 ceramics

• Published in: Journal of alloys and compounds Vol. 527; pp. 157 - 162
• Main Authors: Yao, Y.B., Liu, W.C., Mak, C.L.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 25-06-2012; Elsevier
• Subjects: BiFeO3; Ceramics; Coefficients; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Doping; Electrical conductivity; Electrical properties; Electrical resistivity; Exact sciences and technology; Permittivity (dielectric function); Physics; Pyroelectric; Pyroelectric and electrocaloric effects; Resistivity; Samarium; Sm3+ doping; Pyroelectric; BiFeO3; Sm3+ doping; Electrical conductivity; Vacancies; Cooling; Doping; Bismuth Iron Oxides Mixed; Pyroelectricity; Electrical model; Samarium additions; Sintering; Solid state reaction; BiFe0; Neel temperature; Sm; Permittivity; Activation energy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.02.182

► 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.
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 137μC/m2K as the Sm3+ doping level increased from 1mol% to 8mol%. 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 ∼0.7eV 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.