ChemInform Abstract: Magnetic Coupling Mechanism in A-Site Ordered Perovskite YMn3Al4O12: Extended (Mn-O)-(O-Mn) Superexchange

A-site ordered double perovskites hold promise for potential device applications, where how their magnetic objects actually interact is known to influence functionality. Here, we investigate, by first-principles calculations, electronic and magnetic properties of YMn3Al4O12, and demonstrate that it is an antiferromagnetic insulator. Our calculations reveal the extended (Mn-O)-(O-Mn) superexchange as a primary magnetic coupling mechanism in YMn3Al4O12, and further identify the O-O bonds as a key factor to dominate coupling strength. We suggest that this superexchange mode is the origin of antiferromagnetic behavior, opening an additional avenue to understand magnetic coupling in A-site ordered double perovskites. (C) 2012 Elsevier Masson SAS. All rights reserved.