Extraordinary role of Ca2+ ions on the magnetization of LaFeO3 orthoferrite

Samples of La1-xCaxFeO3 were synthesized in air for 0.05 <= x <= 0.55. X-ray powder diffraction analysis showed that the samples were formed in a single phased orthorhombic structure (Pbnm) where the lattice parameters were calculated and reported. The dc magnetic susceptibility was measured using Faraday's method from room temperature up to about 850 K at five different magnetic field intensities. The obtained results showed that the samples were antiferromagnetic with slight canting of the Fe3+ spins. The substitution of La3+ by Ca2+ ions lowers the Neel temperature. The calculated values of the effective magnetic moment as a function of the Ca2+ concentration were in good agreement with the reported data. The results were interpreted on the basis of the charge difference and the ionic radii of the La3+ and Ca2+ ions. (c) 2005 Elsevier B.V. All rights reserved.