Permeability of Nb and Ta doped lithium ferrite in high frequency range

Nb and Ta doped lithium ferrites with composition of Li0.5Fe2.5O4+xNb2O5 and Li0.5Fe2.5O5+xTa2O5 (where x = 0 , 0.3 , 0.6 , 0.9 , 1.2 and 1.5 wt%) have been prepared by a solid-state reaction method. The effect of Nb2O5 and Ta2O5 on microstructure, magnetic properties like saturation magnetic moment (Ms), coercivity (Hc), retentivity (Mr) and permeability of lithium ferrite have been investigated in the frequency range 1 MHz to 1 GHz. The permeability of Nb2O5 doped lithium ferrite has been found higher (35) than pure lithium ferrite (25) at 1 MHz.