M. A. Ahmed, S. I. El-Dek, E. Dhahri and M.M. Arman
Nanometric multiferroic LaFe1-y yO3, (0.0 ≤ y ≤ 0.03, step 0.01) samples were successfully synthesized using citrate autocombustion method. The X-ray diffraction (XRD) data reveal that all the samples have single phase orthorhmbic structure. The high resolution transmission electron microscope (HRTEM), energy dispersive spectroscopy (EDS) and selected area electron diffraction (SAED) were carried out for the samples. Results of the temperature dependence of molar magnetic susceptibilities (χM) illustrate the antiferromagnetic behavior of the samples. χM of the sample LaFe0.99 0.01O3 was improved by 2.5 times than that of the parent one. The exchange bias (EB) effect was observed for 1st time at room temperature and originated from antiferromagnetic –ferromagnetic (AFM–FM) interface effect. Two conduction mechanisms were found: the small polaron (SP) tunneling and the correlated barrier hopping (CBH). The saturation polarization (Ps) increased by 7.4 times by doping with vacancy content y=0.03. Ferroelectric hysteresis loop assure the presence of the ferroelectric ordering for the samples. The investigated samples could be classified as type I multiferroic materials
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