X-ray diffraction measurements of the cation distributions in spinel structures

X-ray diffraction methods are applied to determine the cation distribution and the oxygen positional parameter in low-substituted magnetites with Al³⁺, Ga³⁺, or In³⁺ as substituents. It is possible to conclude that the tetrahedral site preference increases in the sequence Al³⁺, Fe^{3 +}, In≃Ga³⁺, in good agreement with magnetic properties of similar systems and with theoretical considerations of various authors. The presence of a part of the Al³⁺ ions in tetrahedral sites is Confirmed by means of the Mössbauer effect. Reliability of the methods and errors are discussed. X-ray methods such as these appear to be potentially applicable for industrial checks in ferrite production.