μSR study of iron oxycarbonate Sr4Fe2(CO3)O6 multiferroic material

In this proposal, we wish to study the origin of the multiferroic nature in Sr4Fe2(CO3)O6. In the magnetization data, antiferromagnetic (AFM) ordering appears at TN = 340 K and spin rotation transition (SRT) at TSRT = 210 K. Temperature variation of the electric polarization highlights the possible multiferroism in the material. It is speculated that the canting in the spins locally breaks the inversion symmetry and originate the magnetoelectric effect. In a system, which possesses strong spin-lattice coupling, the lattice modulation is associated with the spin rotation transition and thus, induce polarization. To the best of our knowledge, there is no direct experimental evidence for these speculations. Muon spin rotation and relaxation (µSR) is a technique, which is sensitive to small local magnetic and structural changes and therefore can be exploited to get the required information.