| Popis: |
In this research, the nanosized rare-earth orthoferrites (RFeO3) with R = Dy, Ho, Yb & Lu were synthesized by sol–gel combustion method. Moreover, the effects of varying rare-earth ions on structural, magnetic, and electrical properties of RFeO3 nanoparticles (NPs) have been studied. X-ray diffraction patterns of the prepared samples confirm that all samples are completely single phase with orthorhombic structure and Pbnm space group. The magnetic hysteresis measurements indicated the decrease in the antiferromagnetic nature of RFeO3 from R = Dy to Lu that can be ascribed to non-collinear Fe moments because of the structural distortion. The maximum amount of Hc was ~ 6430 Oe for LuFeO3. The electric hysteresis of these samples exhibited narrow electric field-polarization loops. Both Pr and Ec values for RFeO3 compounds increased from R = Dy to Lu. The frequency response of dielectric constant of RFeO3 is explained based on the dipole relaxation process and the Maxwell–Wagner model. In addition, in the temperature dependence of the dielectric constant is observed an anomaly in the vicinity of Neel temperature (TN) of RFeO3 compounds. The values of TN for RFeO3 (R = Dy, Ho, Yb & Lu) orthoferrites were determined at the temperature of 638, 631, 625, and 619 K, respectively. This occurrence is an evidence for coupling between magnetic and electric orders. |
