Structural dielectric and magnetic studies of ferroelectric ferromagnetic composites

Abstract

Bismuth Ferrite, being a room temperature multiferroic material, possesses great potential for future applicability in many fields. Its antiferromagnetic Neel temperature and ferroelectric Curie temperature are well above room temperature at 653K and 1100K respectively. Despite its huge possible application, it has equally oppressive drawbacks including presence of secondary phases, high leakage current, low dielectric constants etc. making it not feasible for immediate application in use as various electronic components. Extensive studies have been carried out since the onset of the twenty first century. Extensive studies on Bismuth ferrite modified with rare earth have shown promising results and enhancements in its ferroelectric and ferromagnetic properties. Lithium ferrite, a soft spinel ferrite with significant magnetic properties has high applicability in various electronic components including microwave devices, magnetic recording etc. It has high ferromagnetic Curie temperature of 893K. Substitution of transition metals at the Li- and Fe- sites were reported to have an improvement in its dielectric and magnetic properties. Reports on BFO-LFO nanocomposites were also found. But, reports on simultaneous substitution and composite formation were rarely found. The need for nanocomposites arises as all the desired properties are not present in a single phase in required degree for specific applications. And, according to the product property concept, two or more phases having different properties could be combined to enhance the desired properties. Enhanced magnetic and dielectric properties in nanocomposites having BFO as one of its phase were also reported. The desired properties of nanocomposites can be tuned for specific application by tuning the content of the constituent components, modifying the constituent components. The properties can also be tuned by adopting different synthesis methods, controlling the synthesis temperature etc. newline