Mössbauer studies on MnGaxFe2−xO4

Mössbauer studies on MnGaxFe2−xO4 (x=0−1.0) have been made. Measurements at low temperatures in magnetic fields enabled us to determine the cations distribution on tetrahedral (A) and octahedral (B) sites of the spinel structure. Gallium ions show a strong preference for A-sites. Meanwhile, the line broadening and line shapes of the B-site subspectra suggest that the local variation of hyperfine fields at the B-site Fe ions arises from a random substitution of Ga ions in A-sites. Conclusions about the magnetic exchange interactions are presented.