The magnetic properties of oxide spinel Li0.5Fe2.5−2xAlxCrxO4 solid solutions

The exchange interactions (JBB and JAB are the intra and the inter-sublattice exchange interactions between neighbouring spins, respectively) are obtained by using the general expressions of canting angle and critical temperature obtained by mean field theory of Li0.5Fe2.5−2xAlxCrxO4. The expression of magnetic energy of Li0.5Fe2.5−2xAlxCrxO4 is obtained for different spin configurations and dilution x. The saturation magnetisation of Li0.5Fe2.5-2xAlxCrxO4 is obtained with different values of dilution x. The magnetic phase diagram of Li0.5Fe2.5-2xAlxCrxO4 materials is obtained by high temperature series expansions (HTSEs). The critical exponent associated with the magnetic susceptibility of Li0.5Fe2.5−2xAlxCrxO4 is deduced.