MOSSBAUER STUDIES OF MN-DOPED AND AL-DOPED SYNTHETIC ILVAITES

The magnetic properties of the mineral ilvaite are mainly determined b y the coupling between Fe+2 and Fe+3 in the center of oxygen octahedra forming a chain structure. The Mossbauer results for synthesized Mn-d oped ilvaite show that the substitution of Mn at Fe2+ (A) sites, hardl y modifies the temperature-dependent modulated antiferromagnetic struc ture, but has a remarkable influence on the dynamics of domains walls. The substitution of Al at Fe3+ (A) sites leads to a break up of the m agnetic interaction along the chain leading to an inhomogeneous spin f reezing.