Structural, Electrical and Spectral Studies on Double Rare-Earth Orthoferrites La 1 x Nd x FeO 3

Abstract

Samples of double rare-earth ferrite La1 xNdxFeO3 are synthesized by a high-temperature double sintering ceramic technique. X-ray diraction shows that all compounds have an orthorhombic structure. The values of lattice parameter and the volume of the unit cell, changes with increasing Nd 3+ content. The Goldschmidt tolerance factor decreases and goes far from unity with increasing Nd content. The samples containing Nd ions withx = 0.1, 0.2 and 0.3 have higher resistivity than that of LaFeO3, but for x 0.4 the resistivity decreases. The results indicate the presence of extrinsic semiconducting properties up to 100C above which the hopping conduction appears. Thermoelectric power measurements show that the main charge carriers are electrons. The decrease of the Seebeck coecient and the concentration of charge carrier in the region above 100C, indicates the weakening of the hopping conduction mechanism. The samples were characterized for pyroelectric voltage and IR absorption spectra.