Mössbauer studies of ZnCr1.78 57Fe0.02Ga0.2O4 spinel using magnetic fields

Mossbauer57Fe studies have been performed on the ZnCr1.78Fe0.02Ga0.2O4 spinel without and with external field. A spin-spin relaxation model has been used to fit the spectra and is compared to other models. The results are consistent with the existence of magnetic entities, disunited from the infinite matrix, which block progressively at low temperature. The magnetic order of the entities as well as the infinite matrix resembles speromagnetic order.