Mössbauer studies of Mn- and Al-doped synthetic ilvaites

Abstract The magnetic properties of the mineral ilvaite are mainly determined by the coupling between Fe +2 and Fe +3 in the center of oxygen octahedra forming a chain structure. The Mossbauer results for synthesized Mn-doped ilvaite show that the substitution of Mn at Fe 2+ (A) sites, hardly modifies the temperature-dependent modulated antiferromagnetic structure, but has a remarkable influence on the dynamics of domains walls. The substitution of Al at Fe 3+ (A) sites leads to a break up of the magnetic interaction along the chain leading to an inhomogeneous spin freezing.