NONSTOICHIOMETRIC LIZNTI FERRITES FOR MICROWAVE APPLICATIONS

The role of iron defect in the chemical composition, to make up for th e contamination by the steel mins in spinel ferrites of nominal compos ition Li-0.5(1-x+y)ZnxTiyFe[2.5-0.5(x+3y-z-k])MnzO4, where k accounts for the iron defect, is studied through the measurement of M(s) and th e curves of ferromagnetic resonance. Samples are sintered in air and O -2. The ferromagnetic linewidth Delta H decreases in both cases with i ncreasing k, without modifying M(s) noticeably, for k up to 0.05. The asymmetry of the resonance peak implies an anisotropy compensation poi nt for k near 0.05 suggesting that, besides the Fe2+ compensation taki ng place at this value, some phase segregation occurs when k > 0.04, c hanging the composition of the spinel matrix.