“Synthesis and Characterization of Multiferroic Composites"
ferrites, sol-gel. ferroelectric, ferromagentic
Nano-structure ferrites and ferromagnetic-ferroelectric composite materials produced by sol gel method have a great attention in different applications due to their desired properties and applications. Inverse spinel structure Ferrites (MFe2O4), where M is Co and Ni, were prepared by the sol–gel process using metal nitrates as a source for the metal ions and chelating agent citric acid, while lead titanate was prepared by sol-gel process using lead acetate and titanium isopropoxide precursors. The dried gel of ferrites was obtained at 150 oC, while that of lead titanate obtained at 200 oC. The ferrites gel was calcined at 400, 600 and 800 oC and lead titanate gel was calcined at 800 oC. The XRD proved that single phase nanostructure ferrite was obtained for samples calcined at 400, 600 and 800 oC while lead titanate crystallized in tetragonal structure. The composite, (PbTiO3)(1-x) –(MFe2O4)x, (x=10, 20 and 30%), was prepared by in situ sol-gel method and calcined at 800 oC. The XRD of the composites confirm the presence of the spinel ferrites and tetragonalstructure PbTiO3 in the composite system. Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM) were used to study the particles and surface morphology of powder samples, respectively. Fourier Transform Infrared (FTIR) was used to prove the consistence of the chemical bonds of the inverse spinel ferrites and the tetragonal lead titanate. Hysteresis loop was measured for all samples by vibrating sample magnetometer. The hysteretic behavior of the samples proves that they have a ferromagnetic property although the low concentration of ferrites in composite system. The coercivity (HC) change with the condition of preparation of ferriteslike solvents and temperature proves that ferrites are very sensitive to the change of preparation conditions.