Enhanced magnetic and ferroelectric properties of K–Hf substituted BiFeO3 multiferroics for magnetoelectric data storage applications.

Enhanced magnetic and ferroelectric properties have been observed in Hf substituted Bi0.97K0.9Fe1−xHf(3/4)xO3 (0.00 ≤ x ≤ 0.20) nanocrystalline multiferroics which were synthesized via auto combustion sol–gel method. Citric acid was used as a solvent. Structural investigation confirmed the development of pure perovskite rhombohedral distorted phase. The enlargement in cell volume was observed with K–Hf substitution due to lattice distortion and the ionic radii of substituents. Ferroelectric loops showed that maximum polarization (Pmax) was inclined from 0.000376 to 0.391 µc/cm2 as well as remanent polarization (Pr) from 1.000815 to 5.39 µc/cm2. This was due to Hf–K contents which altered Fe–O bond length and increase disturbance in FeO6 octahedra which increase polarization. High values of saturation magnetization (Ms = 4.79 emu/g) and remanent magnetization (Mr = 1.7 emu/g) was attributed to disturbance in antiferromagnetic spin modulated cycloid (λ = 62 nm) structure. Enhancements of magnetic properties along with the formation of P-E loops make these multiferroic nanomaterials the best candidates for magnetoelectric RAMS. [ABSTRACT FROM AUTHOR]