Structural and magnetic properties of solid solutions of lithium ferrite with cadmium ferrite and with lithium aluminate

Measurements of magnetization (at temperatures down to 90°K) have been made by means of a Sucksmith magnetometer on lithium ferrite (LiFe5O8) and the following solid solutions: LiFe5O8¿CdFe2O4 (25, 35, 50, and 75 mol % CdFe2O4), and LiFe5O8¿LiAl5O8 (10, 20, 30, and 40 mol % LiAl5O8). The cation distributions in these materials have also been determined as far as possible by X-ray examination. Magnetic and structural measurements both indicate (a) that cadmium ions enter tetrahedral ion-sites in the first solid-solution series, and (b) that aluminium ions in the second series replace ferric ions in both tetrahedral and octahedral sites, with an increasing preference for octahedral sites as the aluminium content increases. The temperature dependence of magnetization for the materials (revealing cases of Néel´s R-, P-, and probably N-type behaviour) and the effects of changes in g-value for the iron atoms are discussed.