STUDY OF NONSTOICHIOMETRY AND PHYSICAL-PROPERTIES OF THE ND-1-X(BA0.40MG0.60)(1-Y SYSTEM(X)FEO4)

A series of samples of the Nd-1-x((Ba0.40Mg0.60)(1+x)FeO4-y(x = 0.00, 0.10, 0.20, and 0.30) system has been synthesized at 1450 degrees C un der an atmospheric air pressure. The x-ray powder diffraction analysis of the solid solutions assigns the structure of all the compositions to orthorhombic system. Mohr salt analysis shows that tau and y values increase with x value and nonstoichiometric chemical formulas of the system can be formulated from the x, tau, and y values. Oxygen vacanci es are distributed along c-axis in the perovskite layer. The magnetic ordering temperature remains unchanged with x value. Electrical conduc tivity and activation energy depend only on the mixed valence state of Fe ion. Conduction mechanism can be suggested as the hopping of elect ron between e(g) orbitals of Fe3+ and Fe4+ ions through Fe3+-O-Ee(4+) bonds. Magnetic susceptibility and electrical conductivity are discuss ed with the nonstoichiometric chemical formulas.