Effect of Ni-Co codoping on structure and electrical properties of multiferroic BiFeO₃ nanoparticles

Ni and Co doped nanocrystalline BiFeO₃ (BFO) have been prepared using a facile sol-gel technique. The effects of codoping on the crystal structure, morphology and electrical properties are investigated. X-ray diffraction and high-resolution transmission electron microscopy studies confirm the phase purity and growth of BFO nanoparticles. The heat-flow measurement using a differential thermal analyser shows an endothermic peak between 1070 and 1100 K representing ferroelectric to paraelectric phase transition. A systematic electrical conductivity study of these nanoparticles delineates that resistivity increases for doped BFO samples which is very much desirable for device applications of multiferroics.