The sintering phenomena and B-H loop properties of $Li_{0.5}Fe_{2.5}O_4$ with the addition of $Nb_2O_5$ and $V_2O_5$ have been investigated.
Lithium ferrite specimens in the form of toroid core with 0.0026, 0.005, 0.01, 0.02 mole fractions of $Nb_2O_5$ and 0.005 mole fraction of $V_2O_5$ as well as with no additives were prepared by conventional method.
The results showed that Nb ion and V ion had a small solubility in the lithium ferrite, and the solubility of Nb ion was lower than that of V ion.
The additions of $Nb_2O_5$ and $V_2O_5$ lowered the sintering temperature, and the effect of $V_2O_5$ addition was greater than that of $Nb_2O_5$.
The addition of $Nb_2O_5$ resulted in a large and uniform grain size, and the addition of $V_2O_5$ resulted in uniform grain size but the final density was lower than that of the pure specimen. The squareness was increased and the coercive was decreased by the addition of $Nb_2O_5$, and the squareness was slightly decreased and the coercive force was increased by the addition of $V_2O_5$. These effects were explained in terms of the sintered densities and microstructures.
