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Single-phase lanthanum orthoferrite (LaFeO3) was prepared by an auto-combustion method. The analysis of synchrotron room temperature X-ray diffraction (XRD) data confirmed the orthorhombic LaFeO3 perovskite of space group Pnma without any impurity phase. The Scherrer's formula and Williamson-Hall plot based on XRD data were employed to estimate the crystallite size of the prepared sample. For a deeper insight into the crystal structure, high-resolution transmission microscopy imaging (HRTEM) was performed. The estimated values of crystallite size from HRTEM and synchrotron XRD data were coincident. The HRTEM images confirmed the polycrystalline nature of the prepared sample through the obvious lattice planes which are related to (121) plane. Furthermore, the M(H) hysteresis loop of the investigated sample was characterized by a vibrating sample magnetometer (VSM). The magnetic properties obtained through analyzing the magnetization versus temperature M(T) and magnetization versus magnetic field M(H) curves indicated that LaFeO3 possessed weak ferromagnetism at room temperature.

Polyvinyl alcohol (PVA; molecular weight 17,000 g/mol) with additions of several different amounts of magnesium sulfate (molecular weight 246.945 g/mol) was prepared by the casting technique. The dc electric properties of these films were measured in different temperature ranges and the activation energy values as a function of different magnesium sulfate amounts were calculated. The dependency of dc electrical conductivity dc at a certain temperature was found to fit the well-known equation dc ϭ [(1/R) ϫ (t/A)] (⍀ Ϫ1 m Ϫ1 ). The temperature dependency of dc , which suggested an electronic hopping conduction mechanism in a thermally assisted electric field, in addition to some theoretical mechanism were discussed. Also the values of activation energy as a function of different amounts of magnesium sulfate were investigated and it was found that the activation energy values for most samples increase with increased amounts of magnesium sulfate. On the other hand, the nonlinear coefficient parameter as a function of the different amounts of magnesium sulfate was investigated for all the prepared samples.

In this work, we studied the structural and magnetic properties of multiferroic La1-xYxFeO3 perovskites, (x= 0.0, 0.05, 0.1, 0.15, 0.25 and 0.3) which synthesized through Sol-gel auto-combustion technique using a citric acid as a fuel. The room temperature synchrotron X-ray diffraction (XRD) analysis revealed that the all the synthesized samples consisted of the polycrystalline orthorhombic structure perovskites(space group pnma), and tolerance factor confirmed the phase stability of the prepared perovskite system.The Williamson-Hall plot based on synchrotron XRD data were employed to estimate the average particle diameter and varies from 18 nmto 27.8 nm.For a deeper insight of the crystal structure, high resolution transmission microscopy imaging (HRTEM) was performed. The estimated values of crystallite size from HRTEM and synchrotron XRD data were coincident. Many of crystallographic parameters and electron density measurements were calculated by Rietveld refinement of synchrotron XRD data. La1-xYxFeO3 perovskite crystalsarecanted antiferromagnets with a weak ferromagnetism in room temperature.The magnetic properties were gotten through analyzing the magnetization versus temperature M(T) and M(H) hysteresis loop which characterized by a vibrating sample magnetometer (VSM). The molecular structure showed the decrease of the tilting of the octahedra <FeO6> with increasing Y content trying to strengthen the ferromagnetic character. Selected Area Electron Diffraction (SAED) patterns of the investigated samples exhibited spotty ring patterns,confirming the polycrystalline character.The orthoferrite La1-xYxFeO3 crystalsare a promising candidate for optical device applications in broad temperature range and high power system.