Synthesis, Structural and Morphological Properties of Multiferroics

Magnetoelectric multiferroics, showing simultaneous ferroelectric and ferromagnetic ordering, have aroused wide attention in recent years, because they offer a wide range of potential applications in data storage media, spintronics and multi-state memories. [1] The influence of Ho doping on the crystal structure of bismuth ferrite (BFO) nanopowders was investigated. Namely, BiFeO3 and Bi1- xHoxFeO3 ultrafine nanopowders were synthesized by the simple, low-cost and energy-saving hydrothermal method. The diffraction pattern was recorded at room temperature and atmospheric pressure in the absence of any re-heating of the sample. A fitting refinement procedure using the Rietveld method was performed which showed the incorporation of Ho3+ ions in the BiFeO3 crystal lattice, where they substitute Bi3+ ions. All the samples belong to R3c space group. In addition, theoretical investigation using bond valence calculations have been performed in order to mimic pure and Ho doped BiFeO3 compounds produced in the experiment. The optical properties of the material were examined by the spectroscopic ellipsometry method and the energy gap was found to be 2.71 eV. Transmission electron microscopy (TEM) and the scanning electron microscopy (SEM) was used to determine the particle size and morphology. Bi-based oxides will be electrochemically characterized in an aqueous electrolytes of sodium salts by means of Cyclic Voltammetry, to estimate their potential as sodium storage electrodes.