GIANT ENHANCEMENT IN THE PHYSICAL PROPERTIES OF LaFeO3BY SUBSTITUTION OF DIVALENT IONS

摘要

Perovskites with the general formula La_(1-x)M_xFeO_3, x = 0.0 and x = 0.3, M = Ca~(2+),Sr~(2+) and Ba~(2+) were prepared by the double sintering ceramic technique. The X-ray powder diffraction,IR and TEM were carried out to characterize the samples. The molar magnetic susceptibility (χ_M) was enhanced by substitution the divalent metal ion(M~(2+)=Ca~(2+), Sr~(2+) and Ba2+) instead of La+3. The saturation magnetization for both Ca2+ and Sr2+ substituted samples is increased up to 10 times its values for the parent which allow to use these samples in many applications. The Ca substitution improves the conductivity by more than 18 times while the Sr enhances it by 25 times.