Magnetic and dielectric studies of Li1-xCa2xFe5-xO8 for RF/microwave applications

In this work, Li1-xCa2xFe5-xO8, (x =0, 0.003, 0.005, 0.007, 0.01) are synthesized by solid-state reaction methodand are sintered at 1050°C for 5h. The structural, magnetic and dielectric properties have been investigated systematically. The surface morphology of all the sintered samples displayed a dense microstructure. Room temperature magnetization is measured as a function of the applied magnetic field up to 10kOe. The saturation magnetization is found to be decreased with an increase in Ca concentration due to the incorporation of nonmagnetic ions in place of magnetic ions. The sample with x =0.007 displayed the highest saturation magnetization (Ms = 55.22 emu/g) among all the substituted samples. Further, the coercivity and remanent magnetization increased with Ca concentration. The change in magnetization explained on the basis of Neel’s two-sublattice model. The room temperature permeability and permittivity are studied in the broadband frequency range (1MHz-100 MHz). The obtained magnetic permeability (µr = 26.36) and dielectric responses (εr = 1121, tanδ = 0.002) made x =0.007 specimen a promising material for microwave applications.