Synthesis and characterization of CaLaFe11O19

A new ferrimagnetic compound with the chemical formula CaLaFe11O19 has been synthesized by solid state reaction between the respective oxides and their structural, electrical and magnetic properties have been studied. One magnetic Fe3+ ion in CaLaFe12O19 is replaced by La3+ ion. The crystallographic results show the compound is hexagonal magnetoplumbite. The electrical conductivity has been measured from 300 to 800 K. The activation energy changes at Curie temperature (653 K). The compound is ferrimagnetic from 300 to 653 K and above T-c it acts as a paramagnetic. Variation of inverse molar susceptibility has been measured at various temperature in paramagnetic region and Curie molar constant (C-m) is calculated. AC susceptibility measurements are made at room temperature. The Seebeck coefficient (S) measurements show that the compound is n-type. (C) 2001 Elsevier Science B.V. All rights reserved.