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.

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► YMn3Al4O12 is an antiferromagnetic insulator.
► Extended (Mn–O)–(O–Mn) superexchange is the primary magnetic coupling mechanism.
►  O––O bonds are the key factor to dominate coupling strength.