Superexchange Interaction In The A-Site Ordered Perovskite Ymn3al4o12

Crystal structure and magnetic ordering in YMn3Al4O12 are determined by neutron powder diffraction measurement, indicating that S = 2 spins of the A'- site Mn3+ ions are ordered in G-type antiferromagnetic (AFM) arrangement in the Im (3) over bar cubic crystal structure. Using the first-principles electronic structure calculations, it is found that the AFM spin structure is stabilized by the nearest-neighbour (NN) exchange interaction. The underlying mechanism of the NN exchange is revealed to be the antiferromagnetic Mn-O-Mn superexchange interaction from the calculations of electronic transfer integrals.