Synthesis of multiferroic BiFeO۳ nanopowder by sol-gel process

BiFeO ۳ with a perovskite-type structure has been extensively stud ied as a multiferroic ma terial during recent yea rs. It is w ell established that BiFeO۳ is anti ferromagnetic with the Neel temperature TN § ۳۷۰ ƕC and ferroelectric with the Curie temperature TC § ۸۳۰ ƕC [۱-۳]. Because of this magnetoelectric coupling, BiFeO۳ may be used to develop n ovel applic ations such a s spintronic s and senso rs. Purity phase of the BiFeO۳ is important fo r high quality of magne toelectric d evices. Th e first, BiF eO۳ powders have been synthesized by solid-state reacti on of Bi۲O۳ and Fe۲O۳ at temperatu re greater than ۸۰۰ ƕC in micro size with unavoidable impurities such a s Bi۲Fe۴O۹ and Bi۲۵FeO ۴۰ [۴]. It is well know n that BiFe O۳ nanostru ctures exhibit unique electrical, magnetic, and optical properties due to their lo w dimensio n [۵].Therefore, vario us wet chemical methods have been developed to prepare BiFeO۳ nanopowders [۵]. The aim of these meth ods is decre asing of imp urities and purity phase with high quality. In this work, w e synthesized BiFeO۳ nanopowders by a sol- gel method. The effect of annealing temperatu re, values o f pH and r atio of citri c acid and e thylene glycol is investigated.

کلیدواژه ها:

BiFe O۳ ، Nanopow der ، Chemical synthesis ، Multiferro ic materials.